Ollie Watkins’ opener was cancelled out as Swansea City stormed back from a goal down to defeat 10-man Brentford for a place in the FA Cup quarter-finals.

Despite a dominant first half which saw Watkins power home to finish a swift counter-attacking move, the Bees completely capitulated in the second 45 minutes.

Bersant Celina’s free-kick came back off goalkeeper Luke Daniels for an own goal before Daniel James stroked the ball home superbly.

After Celina beat two defenders to secure the third, George Byers rifled in from outside the box to complete the rout.

READ: Player ratings from Brentford's FA Cup capitulation to Swansea City

Thomas Frank made just one change to the side which defeated Aston Villa, with goalkeeper Luke Daniels replacing Daniel Bentley.

After Yoann Barbet was booked for hacking down Daniel James, Oliver McBurnie was inches away from punishing Brentford with a close range header.

But the visitors improved following the early scare to panic Swansea, going close through Neal Maupay and Said Benrahma.

The high-tempo opening exchanges became subdued before Ollie Watkins completed a swift counter-attacking move, thanks to a deft Maupay assist, on 27 minutes.

And a dominant Brentford could’ve doubled their lead soon after had Maupay been a second quicker to Benrahma’s cutback pass inside the 18-yard box.

Swansea boss Graham Potter had his work cut out for him at half time, but what was said must have worked because their performance improved dramatically.

Celina rattled the post with a free-kick before the ball ricocheted off Bees goalkeeper Daniels and into the net for an own goal on 49 minutes.

Soon after it was 2-1 – James’ pace was too much for Mokotjo, bursting into the box from his own half to finish superbly on 53 minutes.

Ezri Konsa would receive his marching orders after wiping out James on the hour mark, his second booking in 13 minutes, but things got a lot worse for Brentford.

Celina collected the ball out wide before dancing past Sergi Canos and Julian Jeanvier to fire past Daniels on 66 minutes.

The tie could, and should, have been over when Celina’s parried effort was stroked home by Connor Roberts – only for the linesman to rule him offside.

With 20 minutes remaining, Frank had introduced Josh Da Silva and Nikolaj Kirk but Brentford had completely crumbled by then.

George Byers arrived late from midfield to fire past Daniels into the bottom corner of the net a few minutes before time.