William Hill League One leaders Inverness slipped to a 2-1 defeat at Montrose, where they finished the game with 10 men.
Caley, beaten by title rivals Stenhousemuir last weekend, had taken an early lead when Alfie Stewart put them ahead in the third minute.
Montrose, though, were back on level terms just after the hour through Blair Lyons – and Inverness defender Ross Millen was shown a straight red card in the aftermath.
After Stewart then saw his free-kick hit the crossbar, Montrose substitute Ker Waddell headed in with 15 minutes left to complete the turnaround.
Stenhousemuir, though, missed the chance to move level at the top after being held to a goalless draw at Alloa, which leaves them two points behind.
Matty Douglas scored a hat-trick as Queen of South moved up to third after a 4-1 win over Hamilton.
Douglas struck twice in the first half to put the Doonhamers in control.
Connor Smith pulled a goal back for Hamilton soon after the restart, but Douglas then completed his treble in the 52nd minute before Jack Stott wrapped things up with a late fourth.
Bottom club Kelty Hearts beat East Fife 1-0 for a first league win since the end of September, with Lewis Moore scoring just before half-time.
Cove Rangers, though, kept themselves four points clear with a 4-0 win at Peterhead, with Mitch Megginson scoring in each half, his second from the penalty spot.
In League Two, Spartans extended their lead at the top of the table to five points with a 3-1 win at bottom club Edinburgh after Mark Stowe scored a hat-trick.
East Kilbride lost ground following a 1-1 draw against Clyde, as both teams finished with 10 men.
John Robertson put East Kilbride in front, before midfielder Sean Fagan was sent off early in the second half for two cautions.
Logan Dunachie equalised in the 68th minute but was then also dismissed – with two minutes left – after his second booking.
Scott Shepherd scored four goals as Forfar thumped Elgin 4-2 at Station Park, where the visitors finished with 10 men following a late red card for defender Jack Murray.
Stranraer twice came from behind as they battled to a 2-2 draw at Annan, while Stirling won 2-1 at Dumbarton with a late goal from Adam Brown.
