Ryan Stevenson hit a first-half hat-trick as Hearts thrashed Kilmarnock 5-0 in the Scottish Premiership at Tynecastle on Sunday.
Billy King and Callum Paterson were also on target early in the second half as Gary Locke's in-form side increased Killie's relegation fears.
Allan Johnston's men remain in the play-off place but four clubs are separated by just two points, with St Mirren now safe on 38 points.