Bradford’s incredible FA Cup run continued as Sunderland became their latest Premier League scalp.
Jon Stead continued his run of scoring in every round to help put the Bantams into the quarter-finals.
Phil Parkinson’s side showed their victory over Chelsea was no fluke, going in front through John O’Shea’s third-minute own goal.
Stead doubled the lead for the League One promotion-chasers with a close-range finish in the 61st minute.
In front of their biggest home crowd for more than 50 years, 24,021 people watched Bradford enjoy a perfect start as O’Shea failed to deal with a deep Filipe Morais free-kick swung in from the right.
The ball reached Billy Clarke and the midfielder’s misdirected shot from inside the area struck Sunderland skipper O’Shea’s right leg to beat keeper Vito Mannone at his near post.
Much of the pre-match talk centred on the condition of Bradford’s pitch, which was further cut up during the warm-ups.
Sunderland initially failed to adapt to the heavy conditions, and were pushed back as the hosts went in search of a second goal.
Stead failed to head in James Meredith’s inviting cross at the near post as Gus Poyet’s Sunderland side endured a torrid opening.
Sunderland finally began to assert themselves and Steven Fletcher had penalty claims turned down when the forward went to ground under Rory McArdle’s clumsy challenge.
It took a good low save from Ben Williams to keep out a powerful deflected drive from full-back Patrick van Aanholt as Sunderland began to press.
At the other end Billy Clarke forced Mannone into action after finding a way past three Sunderland defenders to shoot from 18 yards.
Poyet introduced Connor Wickham at half-time, and Sunderland continued to push forward, with Ricardo Alvarez initially more of an influence after the re-start.
It took a fine intervention from defender Meredith to prevent Adam Johnson from lobbing the equaliser into an unguarded net.
Sunderland looked the more likely at that stage to score, but it was Bradford who claimed the contest’s crucial second goal.
It came from Stead, who claimed a measure of revenge after becoming a figure of ridicule for supporters at the Stadium of Light during a two-year spell on Wearside where he found the net just twice.
Johnson’s attempted clearance was headed back into the Sunderland area by James Hanson and 31-year-old Stead, on loan from Huddersfield, found a way past Wes Brown to shoot beneath Mannone from 12 yards.
Wickham saw a late header saved by Williams as the Sunderland fight-back failed to materialise in the remaining half an hour.
Many fans among the 4,000-strong away support then turned on head coach Poyet.
Although it was the Bradford fans who were serenading the Uruguayan with chants of ‘you’re getting sacked in the morning’.
Bradford boss Phil Parkinson told BBC Sport: “I am obviously delighted with the way we played. We did the right things in the right areas of the pitch. Defensively we were outstanding. I was pleased when Jon Stead put that second goal in, it gave us a bit of breathing space and we saw the game out professionally.
“There is always a danger because the expectancy might have been we would win this one after beating Chelsea but we have kept that underdog spirit. It was a good, old-fashioned cup tie, a really good advert for the FA Cup.
“The pitch was not as bad as it was two or three weeks ago, we played some good stuff at times, so did Sunderland.
“After today we would like another game at home. It is incredible for all the players to experience that sell-out atmosphere. We had all three sides singing and behind the team and it raises the lads to the next level.”
Sunderland manager Gus Poyet told BBC Sport: “It was a proper old-style cup tie. Two teams committed. It would be a mistake, or a deflected shot that would be the difference from the two teams, or a decision from the referee.
“Credit to Bradford, they know how to play these games. It is not humiliating, it is what the cup brings into the equation. If the top teams always beat the smaller teams, then the cup would not exist.”
