Arbroath and Raith Rovers suffer defeats at top of Scottish League One
New signing Brad Spencer scored and was then sent off on his Forfar Athletic debut as his side beat runaway Scottish League One leaders Arbroath 2-0.
But the Red Lichties remain 13 points ahead of Raith Rovers after the Kirkcaldy side lost 2-1 away to relegation-threatened Brechin City.
Third-top East Fife came from 3-1 down to beat Stranraer 4-3.
Bottom side Stenhousemuir beat Airdrieonians 1-0, while Montrose drew 1-1 away to Dumbarton.
Arbroath slumped to only their second league defeat of the season after Connor Coupe broke the deadlock in the Angus derby after 14 minutes.
Spencer, who signed for Forfar from League One rivals Dumbarton, scored with seven minutes remaining before being sent off five minutes later.
Forfar remain fourth after a fourth straight league win after third-placed East Fife battled back to beat Stranraer.
Kevin Smith pulled a goal back early in the second half after Grant Anderson and Innes Cameron had put the hosts in charge, but Joao Vitoria restored the two-goal lead in the 62nd minute on his debut on loan from Airdrieonians.
However, Craig Watson and Anton Dowds both scored in the space of three minutes to level the game before the latter struck the winner with 10 minutes left.
Brechin move above Dumbarton in the relegation play-off spot after their surprise win over Raith Rovers.
Kevin Nesbit scored a minute after coming off the bench in the first half to give Rovers the lead, but Brechin won thanks to second-half goals from Euan Smith and Ross Kavanagh.
Stenhousemuir warmed up for Tuesday's Scottish Cup replay with Aberdeen by beating Airdrieonians thanks to substitute Thomas Halleran's 74th-minute winner but remain bottom, a point behind Dumbarton.
The Sons looked to be heading to victory after Boris Melingui put them ahead with seven minutes remaining on his debut after the striker's move from Brechin.
However, Martin Rennie's 89th-minute penalty secured a point for visitors Montrose.