Striker Calvin Zola and winger Jacques Maghoma bagged a brace each as Burton Albion consigned Oxford United to a third successive defeat.
The scoring began when Zola volleyed home before turning provider for Maghoma to double the lead with a 20-yard shot into the top corner.
Maghoma curled in the home side's third from a free-kick.
One minute later, he supplied a cross for Zola to strike home his second volley of the afternoon.
VIEWS FROM THE DRESSING ROOM:
Oxford United manager Chris Wilder told BBC Radio Oxford:
"We can't hide away from the fact that that is certainly not good enough from us all.
"It's the most disappointing 45 minutes I've seen, we just didn't compete. We showed a little bit of reaction and got ourselves back into the game but made another poor decision.
"In four and half years it is the most disappointing afternoon I've had at the football club.
"It was disappointing to lose Jake Forster-Caskey to injury in the week because he has been fantastic for us. Up to the goal it was okay, but the first goal changed the aspect of the game.
"The main thing I always say about my teams is that they compete and work hard and you have to have those two things to win anything and we didn't today.
"We've got a lot of work to do and we need to get out of this quickly as we have a local derby in the week and there are a lot of questions being asked in that dressing room."
Sorry, we were unable to load match stats, please try again.
Live Text Commentary
Full Time The referee brings the game to a close.90:00 +2:48
Simon Heslop takes a shot. Blocked by Jacques Maghoma.90:00 +1:44
Corner taken by Adam Chapman from the right by-line.90:00 +1:24
Corner from left by-line taken by Adam Chapman.90:00 +1:06
Jacques Maghoma concedes a free kick for a foul on Damian Batt. Free kick taken by Damian Batt.90:00 +0:50
Jacques Maghoma takes a short corner.90:00 +0:18
Short corner worked by Jacques Maghoma.89:42
Free kick awarded for a foul by Damian Batt on Damien McCrory. Jacques Maghoma restarts play with the free kick.86:15
Tom Craddock produces a right-footed shot from the edge of the box and misses to the left of the target.82:01 Substitution
Substitution Tyrone Marsh joins the action as a substitute, replacing Deane Smalley.81:30
Inswinging corner taken by Tony Capaldi from the right by-line.81:10
Shot from just outside the box by Adam Chapman goes over the target.80:24
The referee blows for offside against Justin Richards. Free kick taken by Ryan Clarke.79:26
The ball is delivered by Damian Batt.78:25
Corner from left by-line taken by Adam Chapman.77:55
Jon-Paul Pittman takes a shot. Stuart Tomlinson makes a save.76:44
A cross is delivered by Damian Batt.74:23
Inswinging corner taken right-footed by Adam Chapman played to the near post, save made by Stuart Tomlinson.74:04 Substitution
Substitution Justin Richards comes on in place of Calvin Zola.72:56
Damien McCrory concedes a free kick for a foul on Jon-Paul Pittman. Adam Chapman takes the direct free kick.
Free kick awarded for a foul by Robbie Weir on Adam Chapman. Direct free kick taken by Adam Chapman.69:19
Damien McCrory fires a strike on goal direct from the free kick.69:19 Booking
Booking Michael Raynes receives a caution for unsporting behaviour.69:02
Unfair challenge on Jacques Maghoma by Michael Raynes results in a free kick.65:44
The assist for the goal came from Jacques Maghoma.65:44 Goal scored
Goal! - Calvin Zola - Burton 4 - 0 Oxford A goal is scored by Calvin Zola from inside the area to the bottom left corner of the goal. Burton Albion 4-0 Oxford Utd.65:28
Robbie Weir takes a shot. Michael Raynes gets a block in.64:14 Goal scored
Goal! - Jacques Maghoma - Burton 3 - 0 Oxford Free kick scored by Jacques Maghoma. Burton Albion 3-0 Oxford Utd.63:22 Booking
Booking Jake Wright receives a caution.63:06
Foul by Jake Wright on Calvin Zola, free kick awarded.62:29
The ball is sent over by Tom Craddock, clearance by Anthony O'Connor.60:12
Free kick awarded for a foul by Jon-Paul Pittman on Jacques Maghoma. Lee Bell takes the direct free kick.59:50
Jon-Paul Pittman takes a shot. Stuart Tomlinson makes a save.59:17
Outswinging corner taken left-footed by Tony Capaldi played to the near post, clearance made by Andrew Corbett.58:58
Adam Chapman takes a shot. Lee Bell gets a block in.58:32
Free kick awarded for an unfair challenge on Damian Batt by Lee Bell. Free kick taken by Damian Batt.57:25
Jon-Paul Pittman delivers the ball, save by Stuart Tomlinson.56:46 Substitution
Substitution Matthew Paterson leaves the field to be replaced by Andrew Corbett.54:36
Inswinging corner taken by Adam Chapman from the left by-line, Calvin Zola makes a clearance.54:13 Substitution
Substitution Jack Dyer comes on in place of Cleveland Taylor.53:51
Jon-Paul Pittman takes a shot. Save made by Stuart Tomlinson.52:51
The ball is crossed by Cleveland Taylor, clearance by Michael Raynes.51:20
Centre by Jon-Paul Pittman.50:37
Shot from just outside the area by Matthew Paterson goes over the bar.49:35
Free kick awarded for an unfair challenge on Tony Capaldi by Cleveland Taylor. Free kick taken by Ryan Clarke.46:52
Tom Craddock produces a right-footed shot from deep inside the six-yard box which goes wide of the right-hand post.46:22
Outswinging corner taken right-footed by Adam Chapman from the right by-line to the near post.46:01
Tom Craddock takes a shot.45:49 Substitution
Substitution Tom Craddock joins the action as a substitute, replacing Daniel Boateng.45:02 Substitution
Substitution Jon-Paul Pittman joins the action as a substitute, replacing Sean Rigg.45:01
The second half kicks off.45:00 +2:29 Half time
Half Time The referee blows for half time.45:00 +2:06
Matthew Paterson produces a header from close range which goes wide of the left-hand post.45:00 +1:45
Calvin Zola takes a shot. Save made by Ryan Clarke.45:00 +0:58
Lee Bell decides to take the corner short.44:40
Calvin Zola provided the assist for the goal.44:40 Goal scored
Goal! - Jacques Maghoma - Burton 2 - 0 Oxford Jacques Maghoma fires in a goal from just outside the penalty area to the top right corner of the goal. Burton Albion 2-0 Oxford Utd.44:20
Matthew Paterson takes a shot. Michael Raynes gets a block in.43:47
Cleveland Taylor crosses the ball.42:57
Calvin Zola is ruled offside. Ryan Clarke takes the indirect free kick.39:41
Corner taken by Adam Chapman from the right by-line played to the near post, clearance by Damien McCrory.36:26
Robbie Weir takes a shot. Simon Heslop gets a block in.34:26
Centre by Tony Capaldi.33:49
Simon Heslop takes a shot. Blocked by Robbie Weir.33:03
Robbie Weir gives away a free kick for an unfair challenge on Adam Chapman. Adam Chapman restarts play with the free kick.32:21
Alfie Potter has an effort at goal from just outside the box which goes wide of the right-hand upright.30:27
Robbie Weir gives away a free kick for an unfair challenge on Deane Smalley. Indirect free kick taken by Adam Chapman.28:36
Free kick awarded for a foul by Deane Smalley on Zander Diamond. Indirect free kick taken by Stuart Tomlinson.28:13
The referee blows for offside. Free kick taken by Ryan Clarke.27:22
Centre by Jake Wright, clearance by Anthony O'Connor.24:59 Goal scored
Goal! - Calvin Zola - Burton 1 - 0 Oxford Calvin Zola scores a goal from long distance to the top left corner of the goal. Burton Albion 1-0 Oxford Utd.22:49
Jacques Maghoma crosses the ball, save by Ryan Clarke.17:41
Foul by Deane Smalley on Zander Diamond, free kick awarded. Indirect free kick taken by Stuart Tomlinson.16:38
Damien McCrory takes a shot. Jake Wright gets a block in.16:11
Damien McCrory takes a shot.15:01
Jake Wright gives away a free kick for an unfair challenge on Lee Bell. Strike on goal comes in from Lee Bell from the free kick.14:05
Lee Bell fouled by Damian Batt, the ref awards a free kick. Stuart Tomlinson restarts play with the free kick.13:12
Adam Chapman gives away a free kick for an unfair challenge on Cleveland Taylor. Lee Bell takes the direct free kick.12:42
Foul by Calvin Zola on Michael Raynes, free kick awarded. Indirect free kick taken by Ryan Clarke.10:55
Sean Rigg handles the ball and concedes a free kick. Free kick taken by Stuart Tomlinson.9:39
Deane Smalley takes a shot. Stuart Tomlinson makes a save.9:03
Adam Chapman fouled by Calvin Zola, the ref awards a free kick. Indirect free kick taken by Daniel Boateng.7:53
Corner taken right-footed by Adam Chapman to the near post, Header from close range by Michael Raynes clears the bar.7:28
Robbie Weir takes a shot. Michael Raynes makes a clearance.3:09
Lee Bell takes the outswinging corner, clearance by Daniel Boateng.2:52
Robbie Weir takes a shot. Michael Raynes gets a block in.1:08
Free kick awarded for an unfair challenge on Simon Heslop by Robbie Weir. Ryan Clarke takes the indirect free kick.0:00
The ref blows the whistle to begin the match.
Live data and text provided by our data suppliers