St Mirren stretched their lead at the top of the Ladbrokes Scottish Championship to 11 points following a hard-fought 2-1 win at third-placed Dunfermline.Cammy Smith opened the scoring for the Buddies after 13 minutes when he found the bottom corner for his 11th goal of the season following brilliant build-up play by Lewis Morgan.Former Rangers midfielder Nicky Clark levelled for Dunfermline four minutes after the restart with a close-range header after Jean Yves Mvoto knocked down Michael Paton's long free-kick.However, centre-back Jack Baird won the match for St Mirren with a powerful header from Kyle Magennis' far-post cross after 64 minutes and extended their unbeaten league streak to eight games.