AFC Wimbledon 1 Brentford 3
Ollie Watkins and Justin Shaibu scored extra-time goals, their first for the club, to seal a rare League Cup victory for the Brentford.
In a game full of incident, Watkins flighted a perfect shot into the far corner from inside the box in the 105th minute and Shaibu crashed in an effort late on.
Watkins had been part of the Exeter side which had knocked Brentford out of the competition at the same stage last season, but this time he helped them to only their third win in their last 10 League Cup ties.
They appeared in trouble again when Paul Robinson put Wimbledon ahead on 25 minutes, his deflected shot looping in while his team-mates appealed in vain for a handball against Yoann Barbet.
The Bees responded with a Harllee Dean header and Nico Yennaris shot, both of which went narrowly over, while Romaine Sawyers had an effort beaten away by Dons keeper George Long.
Early in the second half, the Bees were indebted to great work from debutant goalkeeper Luke Daniels to keep them in the game as he tipped Cody McDonald’s header on to the bar and then smothered his follow-up.
But a much-changed Brentford line-up equalised on 69 minutes when Neal Maupay showed tremendous tenacity and strength to hold off a defender on the right-hand side before laying it off to Sawyers to thump home from 20 yards.
Wimbledon almost went back in front immediately but substitute Kwesi Appiah saw an effort cleared off the line while there was further drama at the other end as Long appeared to handle well outside the penalty area as he slid to meet Florian Jozefzoon.
Brentford were much the better side in extra time, with Paul Robinson clearing off the line from Sawyers and Long denying Jozefzoon and Henrik Dalsgaard, but the Dons couldn’t hold out.
Brentford: Daniels; Colin, Dean, Barbet, Chatzitheodoridis (Dalsgaard 97); Yennaris, Mokotjo (McEachran 67); Clarke (Jozefzoon 55), Sawyers, Watkins; Maupay (Shaibu 99).
Subs not used: Bentley, Cole, Mepham.