Brentford were hit by a sucker punch late goal by Bradford City's Peter Thorne as the home side struck a 90th minute leveller to steal a draw.
It looked as if Brentford were going to take a vital win and move a step closer to promotion when on-loan striker Billy Clarke ended a flowing move with a brilliant headed finish in the 63rd minute.
But in stoppage time Thorne forced the ball over the line after Hamer had saved superbly from the experienced striker's low shot after Steve Jones had crossed to the near post.
It was a game that looked likely to produce at least two goals, particularly in an entertaining first half, but both teams missed a number of chances in that opening 45 minutes.
The Bees could have been out of sight by the time a quarter of the game had gone - and Damian Spencer could have had the match ball.
The powerful striker, making his full debut alongside Clarke in attack, headed a David Hunt corner wide at the far post early on and then smashed a volley straight at Bradford goalkeeper Rhys Evans from six yards after a Clarke free kick had been deflected into his path.
Clarke almost created a chance for Sam Wood soon after when he turned Matthew Clarke inside out and flashed a ball across the six-yard box but Zesh Rehman cleared.
Chris Brandon sliced a shot wide at the other end after a Paul Mullin nod down but at the other end Spencer should have scored when a Hunt throw was knocked back across by Clarke to find him four yards out but he headed weakly and Evans saved.
Marcus Bean fired a shot narrowly wide from ten yards after another long throw was half cleared and Evans saved a low Clarke effort soon after.
Bradford had been second best by far in the first half hour but they came into the game as the minutes ticked on.
Ben Hamer had to save well at the feet of Thorne after good work on the right by Mullin and then positioned himself well to hold a Graeme Lee free kick which was drilled past the wall.
Clarke curled a shot wide at the other end after another long throw was half cleared before Brandon missed a golden opportunity late in the first half when he was picked out at the far post by Thorne but Hamer saved superbly with his legs.
The second half had fewer chances but Brentford dominated - Hunt curled a free kick inches over before The Bees opened the scoring
Sam Wood bulldozed his way past Rehman and fed the overlapping Dickson, his cross was pinpoint and Clarke arrived to head powerfully past Evans.
Brentford deserved their lead and although Bradford rung the changes The Bees continued to hold the upper hand.
Clarke fired a low shot wide and substitute Sam Williams came close when his attempted lob from 20 yards was held at full stretch by Evans.
The home side were restricted to pumping balls forward and the Brentford defence held firm for most of the second period.
But just when it appeared Bradford had run out of ideas Thorne forced the ball home to snatch a point.
Bradford City: Evans; Rehman, Lee, M. Clarke, O'Brien; Gillespie (sub Jones 64 mins), McLaren (sub Boulding 75 mins), Furman, Brandon (sub Law 70 mins); Mullin, Thorne
Subs (not used): Arnison, Bullock
Brentford: Hamer; Osborne, Powell, Bennett, Dickson; Newton, Hunt, Bean, Wood; Clarke (sub S. Williams 84 mins), Spencer
Subs (not used): Simon Brown, Halls, Phillips, Dobson
Attendance: 12,832 (553 Bees fans)
Written by Chris Wickham