Bradford scored twice in time added on to beat Colchester 2-0 and make it three consecutive wins in their promotion push.
League Two's leading scorer Andy Cook broke the deadlock with a header from Harry Chapman's cross.
And then he provided the pass for substitute Scott Banks to fire a second past keeper Kieran O'Hara.
It was a tough ending for new Colchester boss Ben Garner, who was watching his first game from the stand.
The 20,383 attendance was a record for a fourth-tier game at Valley Parade - but it was the visitors who carried the threat in the first half.
Bradford were grateful to two good saves from keeper Harry Lewis to deny Colchester.
He clawed away a header from former Bradford defender Connor Wood and then spread himself to block Tom Hopper's shot.
Bradford stepped it up after the break as Sam Stubbs headed wide and Brad Halliday forced a good save from O'Hara.
Matty Platt headed against the post from Adam Clayton's cross before Bradford struck twice in stoppage time.