St Mirren 0-1 St Johnstone
Steven MacLean's first-half volley gave St Johnstone victory in Paisley and left St Mirren in the Scottish Premiership's relegation play-off spot.
MacLean converted David Wotherspoon's cross after a concerted period of pressure from the Perth side.
Michael O'Halloran was prevented from scoring a second for the visitors by Jason Naismith's timely challenge.
Paul McGowan and Josh Magennis threatened for the Buddies but the hosts could not carve out an equaliser.
And, with Ross County drawing with Aberdeen, St Mirren trail the Dingwall side by three points point and are two off Partick Thistle, who host Celtic on Wednesday.
The home team at St Mirren Park had started brightly against top-six St Johnstone, John McGinn's strike drawing a save from goalkeeper Alan Mannus.
St Mirren captain Steven Thompson headed just over and, moments later, Mannus was relieved to see Conor Newton's deflected shot spin onto the roof of the net.
St Johnstone came into the match and O'Halloran could not direct either of his efforts on target after being presented with two decent shooting opportunities.
Back at the other end, Darren McGregor nodded just over for the hosts.
The opening goal arrived when MacLean freed himself at the back post to connect well with Wotherspoon's corner.
The side from Perth were playing their second match without Tommy Wright in the dugout, with the manager recovering from gallbladder surgery.
And they were keen to finish the match as a contest early in the second half when O'Halloran got away a shot only for Naismith to make a last-ditch tackle.
McGowan tested Mannus and Magennis had a header cleared off the line by Steven Anderson as St Mirren toiled.
There were further chances for St Johnstone to add gloss to the scoreline, including O'Halloran being denied by substitute keeper Chris Dilo after he had replaced Marian Kello at the interval.
But, in the end, one goal proved to be enough as Scottish Cup semi-finalists St Johnstone consolidated sixth position, having already made sure of a top-half finish at the weekend.
- 28KelloSubstituted forDiloat 45'minutes
- 24NewtonSubstituted forWyldeat 45'minutes
- 9ThompsonBooked at 77mins
- 10McGowanSubstituted forTealeat 68'minutes
- 7McGinnBooked at 41mins
- 2van Zanten
- 12DunneBooked at 78mins
- 23ClancySubstituted forWrightat 45'minutes
- 7MillarBooked at 57mins
- 9MacLeanSubstituted forMayat 86'minutes
- 10WotherspoonSubstituted forCreggat 80'minutes
- Alan Muir
- Shots on Target