League TwoCambridge United 1 - 2 Grimsby Town FTCameron McJannet struck a stoppage-time winner as Grimsby Town beat third-placed Cambridge United to move into the League Two play-off places.Grimsby looked set to share the points, only for McJannett to scramble the ball home four minutes into added time to inflict Cambridge's second home defeat of the season.The Mariners should have led early on when Justin Amaluzor played Kieran Green through, only for U's goalkeeper Jake Eastwood to deny him.They did open the scoring on 23 minutes as Reece Staunton's cross found Green, who this time gave Eastwood no chance with a firm header.Cambridge almost hit back 11 minutes before half-time when Sullay Kaikai's corner kick was flicked on to Mamadou Jobe, whose effort hit a post.They did equalise on 41 minutes as Adam Mayor did superbly down the left and crossed for Ben Knight to fire home.Knight missed a huge chance to put the U's ahead on the hour when Kaikai was hauled down, only for Jackson Smith to save the penalty kick with his foot, before McJannett won it.Report supplied by PA Media.