Celtic extended their lead at the top of the SPL to five points with a hard-fought 1-0 win over St Mirren.
Neil Lennon's men struggled to impose themselves on the side second bottom in the table, but secured the points thanks to Kris Commons's strike 12 minutes from time.
Commons was thrown into the action in place of Fredrik Ljungberg with 20 minutes to go and his introduction had the desired effect for Celtic. Shaun Maloney was the provider with the pass that was collected by Commons 12 yards out before he lashed past the grasp of Paul Gallacher.
St Johnstone manager Derek McInnes was sent to the stand as Dundee United edged a bad-tempered Tayside derby 2-0 to remain on course for a fourth-place finish.
Referee Mike Tumilty harshly sent off visiting defender Steven Anderson after 15 minutes and then banished McInnes from the touchline after he remonstrated with assistant referee Keith Sorbie in the aftermath of Johnny Russell's controversial opener - claiming the United player had scored from an offside position.
Sorbie had an eventful afternoon. It was his intervention that convinced Tumilty to give Anderson a second yellow card for an apparent foul on Swanson. It seemed clear to everyone inside Tannadice that the United winger had gone down easily and television replays backed this up.
St Johnstone performed admirably with ten men but David Robertson's late second sealed the win for United.
Akpo Sodje netted the only goal of the match to give Hibernian a 1-0 victory over Aberdeen in what was essentially a dead rubber in the depths of the SPL's bottom six.
Sodje rifled home a Matt Thornhill pass after Dons midfielder Peter Pawlett had been caught in possession, despite the home side having seemed the more threatening. But the game quickly degenerated into end-of-season fare, and in the end the single goal proved to be the winner.
Motherwell's place in the top six was confirmed despite a goalless draw at Hearts. Ross Forbes struck the top of the crossbar after 75 minutes as Well were second best in the stalemate but still confirmed their place in the top half of the table after Inverness drew 1-1 at Kilmarnock. Hearts had the better of territory and possession, but struggled to break down a stubborn visiting defence and now have one win in six games.
A swift first-half exchange of goals by Jonny Hayes and Liam Kelly saw Kilmarnock and Inverness share the points in a 1-1 draw at Rugby Park. Hayes put the Highlanders in front after a 10th-minute solo run, but his opener was cancelled out three minutes later by an excellent finish from Kelly for the hosts.