A Caolan Boyd-Munce double helped St Mirren blow Kilmarnock away and keep alive their hopes of a top-six finish in the Scottish Premiership.
Stephen Robinson's side were 2-0 ahead inside nine minutes after Boyd-Munce scored from distance and Roland Idowu rolled in a penalty.
The wind and rain played their part in the game and St Mirren took full advantage with the wind behind in the first-half.
With most people at the SMiSA Stadium expecting a response from Kilmarnock in the second half, it was St Mirren who added to their lead, Boyd-Munce drilling in his second and Mark O' Hara adding a fourth from the edge of the box.
The home fans were in dreamland when Declan John fired home a fifth, with Bruce Anderson's late penalty little consolation for the away side.
Little surprise that St Mirren assistant manager Brian Kerr stated: "We're delighted.
"I think, over the last seven, eight weeks, the performance has always been there, the results haven't quite been there and that's been the frustrating thing for us.
"But to go and get the performance and the result today is very pleasing."