Plymouth blew the League One title race wide open with a 1-0 win at leaders Doncaster.Sonny Bradley's bullet header early in the second half moved second-placed Argyle to within three points of their opponents.Plymouth came with a plan to defend deep and counter attack and it worked to perfection as Doncaster's unbeaten home run was ended one game short of a full year.Argyle were indebted to goalkeeper Luke McCormick for two stunning saves either side of half-time.First he pushed away a downward header from John Marquis and then, after Plymouth had gone ahead, tipped over a rasping volley from James Coppinger.Plymouth's goal came on 50 minutes when Bradley peeled away from his marker and powered in a header at the back post.In the last minute Jakub Sokolik produced a vital block from Tommy Rowe to ensure the win for Plymouth, while a volley from Coppinger bounced narrowly wide in the final seconds.