St Mirren kept themselves in the hunt for fourth place with a comfortable win over below-par Dundee in the Scottish Premiership top six.
Alex Gogic put the visitors ahead at Dens Park, before second-half strikes from Scott Tanser and Toyosi Olusanya.
Michael Mellon did get one back for Dundee late on, but it was a disappointing display from Tony Docherty's side, who have picked up plenty of plaudits so far this season.
St Mirren, meanwhile, go five points clear of sixth-placed Dundee and six behind Kilmarnock, who visit Rangers on Sunday.
A fifth-placed finish would see St Mirren go into the second qualifying round of the Europa Conference League.
The importance of this game was not lost on either manager before kick-off. If they are to pick up any points in this top six, it would most likely be in this game.
St Mirren started better, with no scars from November's 4-0 loss at Dens Park visible. Tanser was the first to go close, picking up a long free-kick in the box and firing over from close range.
Neither side looked particularly clinical, until Gogic scored just before the break. Ryan Strain's cross bobbled around the box, with the Cypriot popping up at the front post to knock it in from a few yards out.
The second-half started in a similarly pedestrian fashion, with Dundee's defence particularly guilty of winding down before the summer.
They were statuesque when defending a simple lofted ball towards the box on the hour mark, allowing James Bolton to nod down to Tanser. He flicked round Aaron Donnelly and drilled into the bottom corner, with all the time in the world to finish.
Olusanya had a chance to make it 3-0 when he was played through on goal by two Dundee mistakes, but Jon McCracken made a good save.
He would make no such mistake when gifted his next chance. Keanu Baccus and Mikael Mandron were allowed to tee the ball up to unmarked Olusanya, who fired in from about four yards out.
Dundee did get one back. St Mirren went to sleep from a set-piece, with Owen Dodgson's free-kick knocked to the back post by Donnelly, where Mellon rose to nod in.
Player of the Match - Alex Gogic (St Mirren)
Robinson right to celebrate milestone - analysis
Dundee have battled hard this year, but this was comfortably one of their poorest performances of the season.
They looked tired at the back, and they really missed the leadership of defensive anchor Joe Shaughnessy.
Robinson - celebrating his 100th game as St Mirren manager - got his tactics right, and saw his stronger squad assert their dominance throughout.
He made the point pre-game that not many managers make it to 100 games these days, and he's quite right.
His longevity - two and a half years is now a very long stint in managerial terms - should be lauded.
What next?
Dundee visit Tynecastle next Saturday to face Hearts, while St Mirren host Kilmarnock at the same time (both 15:00 BST).
