Match ends, Albion Rovers 0, St. Johnstone 4.
Chris Kane scored a hat-trick as St Johnstone beat Albion Rovers to set up a Scottish Cup fifth-round trip to face Premiership rivals Hearts.
Kane, who recently returned from a loan spell at Queen of the South, volleyed Saints ahead early on.
Teenager Kyle McClean notched his first St Johnstone goal when he connected with Kane's cross after the break.
Kane latched on to Liam Craig's chip to head home his second and soon struck to complete his first Saints treble.
Weather had caused the tie at Cliftonhill to be postponed twice but it survived a Monday afternoon pitch inspection to go ahead at the third time of asking.
St Johnstone boss Tommy Wright had promised changes following Saturday's 3-1 defeat at home to Partick Thistle.
Kane was one of the eight players brought into the starting line-up, having come off the bench at the weekend, and the 23-year-old forward netted his first Saints goal of the season to add to the five he got at Queens earlier in the campaign.
Joe Shaughnessy's throw-in was helped on by a team-mate's head for Kane to meet it sweetly and fire past on-loan Rangers goalkeeper Kieran Fisher.
That goal may have dampened League One Albion Rovers' enthusiasm but they got a foothold in the game with Connor Shields in-particular causing the visitors problems.
Ross Davidson tested Saints keeper Alan Mannus from distance and Kane had another effort wide before the break.
Saints came out for the second half refocused and soon doubled their advantage.
Kane turned provider with a cross and McClean - making his first start - struck from close range.
The more experienced Liam Craig had a hand in the third goal, lifting the ball on to the diving head of Kane.
And Kane's confidence was further bolstered with a solid strike for Saints' fourth as they completed a professional performance.
Albion Rovers manager Brian Kerr: "It's a poor start, you don't want that in any game never mind a Scottish Cup tie against a Premier League side.
"We rally very well, see out the first half and start having a decent wee bit of pressure on them, without creating any real clear cut chances.
"We lose another bad goal, probably should deal with it better. Disappointing that one.
"The boys that were in there gave us a great shift, great work ethic. Poor defending's cost us."
St Johnstone manager Tommy Wright: "We had to come here with the right attitude and be professional and the start of the game was exactly what we wanted.
"It was a difficult pitch and I thought we played the conditions well. Second half, we did try and play a little bit more.
"Really pleased with the result and the scoreline and the performance overall. Pleased for some of the younger players that came in.
"[Chris Kane showed] great technique for the first one and he's in the right position for the header."
- 6HolmesSubstituted forGallagherat 83'minutes
- 8DavidsonBooked at 29mins
- 7ShieldsBooked at 28mins
- 10HigginsSubstituted forWattersat 74'minutes
- 9VictoriaSubstituted forGuthrieat 74'minutes
- 19John Queen
- 5ShaughnessyBooked at 34mins
- 4AlstonSubstituted forComrieat 69'minutes
- 8DavidsonBooked at 30minsSubstituted forMcCannat 71'minutes
- 25KaneSubstituted forWotherspoonat 83'minutes
- Mat Northcroft
- Shots on Target
Second Half ends, Albion Rovers 0, St. Johnstone 4.
Attempt saved. Michael McMullin (Albion Rovers) header from the centre of the box is saved in the centre of the goal.
Corner, Albion Rovers. Conceded by Jason Kerr.
Attempt saved. Alistair McCann (St. Johnstone) right footed shot from the right side of the box is saved in the centre of the goal.
Ross Davidson (Albion Rovers) wins a free kick in the defensive half.
Foul by Alistair McCann (St. Johnstone).
Attempt missed. John Guthrie (Albion Rovers) right footed shot from outside the box is close, but misses to the left.
Corner, Albion Rovers. Conceded by Alistair McCann.
Corner, Albion Rovers. Conceded by Aaron Comrie.
Corner, St. Johnstone. Conceded by Craig McLeish.
Kyle McClean (St. Johnstone) wins a free kick on the left wing.
Foul by Connor Shields (Albion Rovers).
Attempt missed. Gary Fisher (Albion Rovers) left footed shot from outside the box is too high.
Substitution, St. Johnstone. David Wotherspoon replaces Christopher Kane.
Substitution, Albion Rovers. Anthony Okane replaces Graeme Holmes.
Foul by Denny Johnstone (St. Johnstone).
Graeme Holmes (Albion Rovers) wins a free kick in the attacking half.
Attempt missed. Connor Shields (Albion Rovers) header from the centre of the box is close, but misses to the left.
Connor Shields (Albion Rovers) wins a free kick on the right wing.