Two second-half goals from Billy Sharp maintained Southampton's five-point lead at the top of the Championship.
Sharp struck twice in the space of 17 minutes to increase his former club's relegation worries.
Doncaster fell behind when Sharp headed home Daniel Fox's corner before a mistake by Habib Beye allowed him to make it 2-0.
The visitors went close through Frederic Piquionne when the game was still goalless.
DID YOU KNOW?
Billy Sharp scored 40 times in 82 league appearances for Doncaster
Doncaster, five points from safety with eight games remaining, are running out of matches to save themselves.
Southampton never looked back after Piquionne headed over a golden chance from Simon Gillett's eighth-minute cross.
The leaders quickly settled and Adam Lallana could have opened the scoring after a neat exchange with Sharp, but his effort was blocked.
The traffic was becoming one way and, after Rickie Lambert had a shout for a penalty turned down, Sharp went close with a header which went wide of the post.
The opener eventually came in the 58th minute when Sharp, a £2m signing from Doncaster in January, reacted quickest to get on the end of Fox's inviting corner.
And Sharp sealed the points with 15 minutes remaining when he capitalised on some poor defending from Beye before firing past Carl Ikeme.
Southampton manager Nigel Adkins: "Billy Sharp has scored two really good goals for us and it's a great three points to cap off a very good week.
"It was in the tea-leaves (for Sharp to score). He's worked very, very hard behind the scenes. Since he's joined us, his attitude has been top drawer.
"And the big thing is, here we're not just relying on one person to score the goals. It's 72 league goals we've scored now. We've got some exceptionally good goalscorers and strikers here."
Doncaster manager Dean Saunders said: "The ref cost us the game. He gave them a corner which was never a corner. They scored from the corner. It was a mistake for the second goal.
"It's disappointing we lost points against a top of the league side.
"I think it's typical we sold Sharp to Southampton and then he scores two goals against us. He came back to haunt us."
- 01 Davis
- 06 Fonte
- 12 Butterfield
- 13 Fox
- 26 Hooiveld
- 04 Schneiderlin
- 08 Cork
- 20 Lallana (Hammond - 78' )
- 33 De Ridder (Barnard - 67' )
- 07 Lambert (Chaplow - 49' )
- 11 Sharp Booked
- 03 Harding
- 16 Martin
- 14 Hammond
- 18 Chaplow
- 09 Barnard
- 27 Ikeme
- 11 Lockwood Booked
- 31 Ilunga
- 39 Chimbonda
- 41 Beye
- 16 Oster Booked (Robert - 90' )
- 17 Barnes (Brown - 79' )
- 18 Gillett Booked
- 26 Coppinger (Bennett - 65' )
- 10 Diouf Booked
- 19 Piquionne
- 03 Friend
- 09 Brown
- 22 Robert
- 23 Bennett
- 49 Bagayoko
Live Text Commentary
Full Time The final whistle is blown by the referee.90:00 +5:13
Free kick awarded for a foul by Jack Cork on Simon Gillett. El-Hadji Diouf restarts play with the free kick.90:00 +3:26
Free kick awarded for a foul by Daniel Fox on Herita Ilunga. Carl Ikeme takes the direct free kick.90:00 +2:49
Free kick awarded for a foul by Pascal Chimbonda on Lee Barnard. Daniel Fox takes the direct free kick.90:00 +2:33
Frederic Piquionne is caught offside. Direct free kick taken by Kelvin Davis.90:00 +0:57 Substitution
Substitution John Oster goes off and Fabien Robert comes on.85:09
Foul by Morgan Schneiderlin on Kyle Bennett, free kick awarded. Pascal Chimbonda restarts play with the free kick.84:29
Chris Brown fouled by Jose Fonte, the ref awards a free kick. John Oster takes the direct free kick.83:42
El-Hadji Diouf is ruled offside. Kelvin Davis takes the free kick.83:29
Centre by El-Hadji Diouf, Billy Sharp gets a block in.82:09
El-Hadji Diouf delivers the ball.81:35
A cross is delivered by Danny Butterfield, save by Carl Ikeme.80:25
Danny Butterfield challenges El-Hadji Diouf unfairly and gives away a free kick. Free kick taken by El-Hadji Diouf.78:51 Substitution
Substitution Chris Brown is brought on as a substitute for Giles Barnes.78:36
Effort from the edge of the area by Richard Chaplow goes wide of the right-hand upright.77:40 Substitution
Substitution Adam Lallana leaves the field to be replaced by Dean Hammond.77:05
El-Hadji Diouf sends in a cross, save by Kelvin Davis.76:17 Booking
Booking John Oster is given a yellow card.75:17 Booking
Booking The referee books Billy Sharp for unsporting behaviour.74:19 Goal scored
Goal! - Billy Sharp - Southamp'n 2 - 0 Doncaster Goal scored by Billy Sharp from inside the penalty area to the bottom left corner of the goal. Southampton 2-0 Doncaster.
Booking El-Hadji Diouf receives a caution.70:57
Free kick awarded for a foul by Adam Lockwood on Lee Barnard. Free kick taken by Daniel Fox.66:34 Substitution
Substitution Lee Barnard on for Steve De Ridder.66:11
The ball is delivered by Richard Chaplow, Close range header by Billy Sharp misses to the right of the goal.64:46 Substitution
Substitution (Doncaster) makes a substitution, with Kyle Bennett coming on for James Coppinger.62:19
El-Hadji Diouf produces a cross, Morgan Schneiderlin makes a clearance.60:35
Outswinging corner taken right-footed by El-Hadji Diouf from the right by-line to the near post, clearance made by Richard Chaplow.60:27
The ball is sent over by El-Hadji Diouf, blocked by Adam Lallana.59:28
Pascal Chimbonda fouled by Billy Sharp, the ref awards a free kick. El-Hadji Diouf takes the direct free kick.59:12
Richard Chaplow challenges Herita Ilunga unfairly and gives away a free kick. Free kick taken by Herita Ilunga.57:32
The assist for the goal came from Daniel Fox.57:32 Goal scored
Goal! - Billy Sharp - Southamp'n 1 - 0 Doncaster Billy Sharp scores a goal from close in to the top left corner of the goal. Southampton 1-0 Doncaster.57:00
Corner taken by Daniel Fox from the right by-line,56:08
Richard Chaplow delivers the ball.56:01
The ball is crossed by Steve De Ridder, clearance made by Giles Barnes.55:31
Corner taken by Adam Lallana from the left by-line, Pascal Chimbonda manages to make a clearance.55:26
Steve De Ridder sends in a cross, Habib Beye gets a block in.54:58
Foul by Simon Gillett on Morgan Schneiderlin, free kick awarded. Kelvin Davis takes the free kick.54:20
Adam Lallana concedes a free kick for a foul on Pascal Chimbonda. Free kick taken by Carl Ikeme.52:47
Billy Sharp takes a shot. Save by Carl Ikeme.52:26
The ball is crossed by Richard Chaplow, clearance made by Habib Beye.51:30
Simon Gillett produces a cross.50:09
Giles Barnes fouled by Jose Fonte, the ref awards a free kick. Carl Ikeme takes the direct free kick.49:43 Booking
Booking Simon Gillett is given a yellow card.49:24
Simon Gillett gives away a free kick for an unfair challenge on Richard Chaplow. Daniel Fox takes the direct free kick.48:37 Substitution
Substitution Richard Chaplow replaces Richard Lambert.48:12
The ball is crossed by El-Hadji Diouf.47:57
Frederic Piquionne takes a shot. Blocked by Adam Lallana.46:36
The ball is sent over by Herita Ilunga, clearance by Jose Fonte.45:55
Free kick awarded for an unfair challenge on Adam Lockwood by Danny Butterfield. Direct free kick taken by Herita Ilunga.45:01
The second half begins.45:00 +2:05 Half time
Half Time The first half comes to an end.44:49
Danny Butterfield crosses the ball, Carl Ikeme makes a save.42:39
Adam Lallana takes a inswinging corner from the left by-line to the near post.42:17
A cross is delivered by Daniel Fox, Steve De Ridder takes a shot. Blocked by Adam Lockwood.40:13
Foul by Herita Ilunga on Steve De Ridder, free kick awarded. Daniel Fox sends in a cross, Billy Sharp has a headed effort at goal from close range which goes wide left of the target.35:33
Danny Butterfield restarts play with the free kick.35:33 Booking
Booking Adam Lockwood receives a yellow card.35:28
Free kick awarded for an unfair challenge on Steve De Ridder by Adam Lockwood.34:03
Danny Butterfield sends in a cross, blocked by El-Hadji Diouf.33:44
Unfair challenge on Richard Lambert by Adam Lockwood results in a free kick. Daniel Fox takes the free kick.32:14
Frederic Piquionne concedes a free kick for a foul on Jose Fonte. Jose Fonte takes the direct free kick.31:15
John Oster challenges Jack Cork unfairly and gives away a free kick. Free kick taken by Jack Cork.30:24
The ball is delivered by Jack Cork, save by Carl Ikeme.30:09
The ball is crossed by Steve De Ridder, Giles Barnes makes a clearance.29:59
Steve De Ridder crosses the ball, Habib Beye makes a clearance.28:32
Free kick awarded for an unfair challenge on James Coppinger by Daniel Fox. Carl Ikeme takes the free kick.28:20
The ball is crossed by Danny Butterfield, clearance made by Pascal Chimbonda.27:38
Headed effort from inside the area by Billy Sharp misses to the right of the target.24:45
The offside flag is raised against Frederic Piquionne. Jose Fonte takes the free kick.24:23
Adam Lallana takes a shot. Habib Beye gets a block in.23:48
Free kick awarded for a foul by Simon Gillett on Steve De Ridder. Kelvin Davis takes the direct free kick.23:05
Morgan Schneiderlin concedes a free kick for a foul on El-Hadji Diouf. Direct free kick taken by Carl Ikeme.21:52
Steve De Ridder crosses the ball, clearance made by Habib Beye.17:57
Free kick awarded for an unfair challenge on James Coppinger by Morgan Schneiderlin. Free kick taken by Pascal Chimbonda.17:48
Adam Lallana produces a cross, James Coppinger gets a block in.16:16
Shot from outside the area by Simon Gillett misses to the left of the target.15:54
Corner taken by El-Hadji Diouf from the left by-line played to the near post, Jos Hooiveld manages to make a clearance.15:38
El-Hadji Diouf takes a shot. Clearance made by Jose Fonte.13:04
Steve De Ridder sends in a cross, save by Carl Ikeme.12:55
The ball is swung over by Steve De Ridder, Habib Beye manages to make a clearance.11:29
El-Hadji Diouf takes a inswinging corner from the left by-line to the near post, Morgan Schneiderlin manages to make a clearance.9:42
Herita Ilunga concedes a free kick for a foul on Steve De Ridder. Free kick crossed left-footed by Daniel Fox from right wing, clearance by Adam Lockwood.9:25
Unfair challenge on Morgan Schneiderlin by El-Hadji Diouf results in a free kick. Danny Butterfield takes the direct free kick.8:29
Shot from long distance by Richard Lambert goes wide of the left-hand upright.8:04
Simon Gillett produces a cross, Close range header by Frederic Piquionne goes wide of the left-hand upright.7:38
El-Hadji Diouf crosses the ball, clearance by Daniel Fox.0:48
Free kick awarded for an unfair challenge on Carl Ikeme by Adam Lallana. Direct free kick taken by Carl Ikeme.0:37
Danny Butterfield sends in a cross.0:00
The match has kicked off.
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