The Spiders had only needed a point to secure top spot before the league splits.
Elgin slipped two points off the play-off places with the draw, as fourth-placed Stranraer recorded a 2-0 win at Albion Rovers.
James Hilton opened the scoring in the 43rd minute and substitute Joao Vitoria added a second with six minutes left.
Second-placed Edinburgh City strengthened their grip on a play-off place with a 1-0 win at third-placed Stirling.
Ousman See's 35th-minute goal moved the visitors three points ahead of their opponents.
Annan thrashed Stenhousemuir 5-1. Mark McGuigan had given the visitors a seventh-minute lead but within three minutes they trailed as Nathan Flanagan and Tony Wallace struck. Wallace added his second in the 27th minute and second-half goals from Aidan Smith and Darren Christie wrapped up a resounding win.
Elsewhere, rock-bottom Brechin held Cowdenbeath to a goalless draw.