Blackpool's winless run was extended to five games as they were held 1-1 at home by fellow Sky Bet League Two play-off chasers Colchester.The Seasiders struck with the first real chance after 12 minutes. Nathan Delfouneso jinked past his man and delivered a pinpoint chip into the area, where Jamille Matt turned the ball home from three yards.Blackpool goalkeeper Sam Slocombe denied Matthew Briggs with a sensational save to push the ball behind after 17 minutes, but the visitors did equalise from the resulting corner as Kurtis Guthrie prodded in from close range after a goalmouth scramble.Somehow, Colchester failed to re-take the lead on the stroke of half-time. Slocombe produced a brilliant save from George Elokobi's close-range effort, before Guthrie headed against the bar from two yards.Blackpool should have clinched the win 15 minutes from time, as Tom Aldred was found unmarked from a corner, but he headed wide from eight yards.And Colchester finished the game with 10 men, after substitute Sean Murray was shown a straight red for a bad tackle on Jim McAlister in injury time.