Antoni Sarcevic (centre) scored his third of the season to help bring Cardiff's unbeaten start to League One to an end
Bradford City tore up Cardiff City's unbeaten start to the season to replace them at the top of League One.
First half goals from Tommy Leigh and Antoni Sarcevic were added to by Josh Neufville soon after the interval to hand the Bantams a handsome victory.
Callum Robinson did pull one back as the hosts finished strongly, but - having missed chances earlier in the game - it was not enough to prevent a first defeat under head coach Brian Barry-Murphy.
Graham Alexander's Bradford side have now won six of their nine games following promotion, with the 2,000-strong travelling contingent deservedly enjoying the moment.
Their celebrations started after 16 minutes when Neufville's short corner teed up the unmarked Leigh to smash home his first Bradford goal from the edge of the area.
Then, with half hour played, Sarcevic beat the offside trap and tempted Gabriel Osho into a foul before converting the resulting spot kick.
Yousef Salech and Cian Ashford were both guilty of failing to convert Cardiff chances before hopes of a comeback were effectively ended when Neufville slotted home from the far post after being picked out by Will Swan's outside of the boot cross just four minutes into the second-half.
Salech hit the woodwork before a series of ricochets from a corner allowed Robinson to squeeze home a consolation with 13 minutes remaining, but the defeat saw Cardiff slide to fourth in the table, three points behind Bradford, albeit with a game in hand.
Analysis: Bradford remind Cardiff of tests to come
From Cardiff's point of view, there had been little sign of this coming.
While the performance in last weekend's draw at Stockport had been underwhelming, the manner of the fightback at Edgeley Park suggested they had and answered some questions about this youthful side's resilience.
Indeed, the fact more than 20,000 braved the south Wales weather said plenty about the renewed hope and expectation created by their longest unbeaten league run at the start of a season for 17 years.
With the sides starting the day first and second in the table, it added to a sense of early-season significance.
But it was Bradford – urged on by vocal support and on the back of a big derby win over Huddersfield – who raised their game.
The side still using the momentum from their League Two promotion had an intensity Cardiff had not faced so far this season.
They created space wide for their counter attacks and were clinical.
Cardiff, who had conceded only twice before this game – each time from the penalty spot – looked rattled and unsure of how to stop the attacks.
Gabriel Osho's smile – on his first start, no less - as he foolishly was tempted into a rash dive to concede the penalty showed he should have known better.
Some naivety on Cardiff's part, plenty of street smarts from Bradford.
To Cardiff's credit, the bounce of the ball may have been kinder to them when they attacked, and this would have been a different match had good openings not been ended by tame or poor efforts.
But it was a reminder that for all the early season promise, Cardiff remain a work in progress.
Bradford manager Graham Alexander said the win against Cardiff was "brilliant to witness"
