Match ends, Kilmarnock 3, St. Johnstone 0.
Kilmarnock recorded their first victory under new manager Lee Clark, which should ease the automatic relegation fears for the Rugby Park club.
Kris Boyd opened the scoring with a free-kick midway through the first half, giving the hosts a deserved lead.
Kallum Higginbotham netted a back-post header after the break.
Liam Craig had a headed goal chalked off, before Boyd slammed home a late penalty won by Rory McKenzie. Despite losing, Saints secured a top-six place.
Victory lifts the Ayrshire side eight points clear of bottom side Dundee United and maintains the four-point gap between Killie and 10th-placed Hamilton Academical.
Eager hosts get reward
Having improved defensively, Kilmarnock had struggled for goals since the arrival of Clark in mid-February but after a slow start the home side started to create chances.
A great cross from Josh Magennis found Boyd in the box and his shot beat Alan Mannus only to his the post.
The goal-hungry Kilmarnock faithful would get the breakthrough they desperately craved. A free-kick was awarded on the edge of the St Johnstone area and Boyd fired into the bottom corner - his first goal since December.
There was a huge sense of relief in the wild celebrations, from both players and fans.
St Johnstone tried to respond and almost equalised through Craig, but his close-range shot was superbly saved by the outstanding Jamie MacDonald.
Kilmarnock almost went further in front, Higginbotham playing the ball into the path of Boyd to pull the trigger but Tam Scobbie appeared from nowhere to make a vital block.
Immediately after that Kilmarnock had the ball in the net, Higginbotham with the strike but it was ruled out for offside.
Magennis went close either side of half-time and Scobbie had a chance to shoot for Saints but blazed high into the stand.
Kilmarnock were soon 2-0 in front. Magennis crossed from the right and Higginbotham made no mistake with a downward header at the back post.
Craig then netted with a header at the other end but a push on Mark O'Hara meant there was no goal.
St Johnstone's Bulgarian defender Plamen Krachunov was next to be denied, his header brilliantly saved by MacDonald.
Kilmarnock would wrap up all three vital points right at the end. McKenzie was fouled in the box and from the spot Boyd was on target again as the home side claimed what could be a huge win as they attempt to beat the drop.
- 14O'HaraBooked at 16mins
- 4AddisonBooked at 78mins
- 23KiltieBooked at 23mins
- 11HigginbothamSubstituted forMcKenzieat 75'minutes
- 28MagennisBooked at 33mins
- 22FisherBooked at 23mins
- 16SwansonSubstituted forCumminsat 79'minutes
- 25KaneSubstituted forSuttonat 79'minutes
- Crawford Allan
- Shots on Target
Second Half ends, Kilmarnock 3, St. Johnstone 0.
Gary Dicker (Kilmarnock) wins a free kick in the defensive half.
Foul by Darnell Fisher (St. Johnstone).
Goal! Kilmarnock 3, St. Johnstone 0. Kris Boyd (Kilmarnock) converts the penalty with a right footed shot to the bottom left corner.
Penalty Kilmarnock. Rory McKenzie draws a foul in the penalty area.
Penalty conceded by Joe Shaughnessy (St. Johnstone) after a foul in the penalty area.
Attempt missed. Greg Kiltie (Kilmarnock) right footed shot from the right side of the box is close, but misses to the right.
Corner, St. Johnstone. Conceded by Lee Hodson.
Attempt saved. Chris Millar (St. Johnstone) right footed shot from outside the box is saved in the top left corner.
Substitution, St. Johnstone. Graham Cummins replaces Danny Swanson.
Substitution, St. Johnstone. John Sutton replaces Christopher Kane.
Foul by Miles Addison (Kilmarnock).
Danny Swanson (St. Johnstone) wins a free kick on the left wing.
Miles Addison (Kilmarnock) is shown the yellow card for a bad foul.
Substitution, Kilmarnock. Rory McKenzie replaces Kallum Higginbotham.
Corner, St. Johnstone. Conceded by Jamie MacDonald.
Attempt saved. Plamen Krachunov (St. Johnstone) header from the centre of the box is saved in the centre of the goal.
Corner, St. Johnstone. Conceded by Mark O'Hara.
Foul by Julien Faubert (Kilmarnock).