St Johnstone moved a major step closer to sealing fourth spot in the Premiership by securing a 2-1 victory over Motherwell at Fir Park.Steven MacLean and Danny Swanson struck late in the first half for Saints to make it three times this season that Tommy Wright’s side have come from behind to beat Motherwell.The win moved St Johnstone five points ahead of their opponents as they vie for fourth, which carries roughly #100,000 more in prize money than fifth place and the same amount again over sixth spot.Motherwell went ahead inside four minutes after St Johnstone goalkeeper Zander Clark sliced a first-time clearance straight to the head of Scott McDonald, who guided the ball home. Clark was knocked over by Chris Cadden after the Motherwell midfielder tried to close him down, but there was little protest from the visitors.Motherwell sought to build on their lead and Marvin Johnson was creating chances with some skilful and pacey runs from left-back, where he was standing in for the suspended Steven Hammell.Both Lionel Ainsworth and McDonald shot wide from decent chances created by Johnson and Cadden volleyed straight at Clark from Louis Moult’s knockdown.St Johnstone’s best early effort came when Liam Craig hit the post from 30 yards and they gradually came more into the game. MacLean had a deflected effort saved before levelling in the 34th minute. Saints attacked in numbers and the striker found space to knock home Brian Easton’s cross from six yards.Murray Davidson went off injured for the visitors before Motherwell came back into it, Cadden causing danger with a low cross before Johnson curled over.But the Perth side went in front in the 45th minute. Motherwell right-back Kieran Kennedy got caught out by a flick-on off David Wotherspoon’s cross and the ball looped to Swanson, who slid the ball inside the near post.McDonald came close from long range just after the break but Saints soon had two good chances to move further ahead, Joe Shaughnessy heading over before Connor Ripley stopped Wotherspoon’s strike.Darnell Fisher, already booked for a foul on Johnson, got away with pulling back the same player, who had now moved further forward as Motherwell chased an equaliser.Despite plenty of possession inside the Saints half, the home side could not carve out a clear chance as the visitors put up as formidable a defence as the dozens of extra stewards who appeared in the closing stages to prevent any end-of-season pitch invasion.