Brentford twice fought back before beating Premier League West Brom 5-4 on penalties in the Carabao Cup.
But Emiliano Marcondes’ superb overhead kick and a Marcus Forss spot-kick drew the Bees level to force the shootout.
Christian Norgaard scored the winning penalty after Grady Diangana’s effort had been saved.
Brentford will host Premier League Fulham or Championship rivals Sheffield Wednesday in the fourth round. The Bees have never progressed beyond the fourth round of this competition in their history.
Ties are due to take place in the week commencing 28 September.
‘A very good game between two rivals’
West Brom beat Brentford to automatic promotion from the Championship last season before Thomas Frank’s side lost in the play-off final to Fulham, but the Bees gained revenge.
“That’s the past, this is the future,” said Brentford boss Thomas Franks. “We are pleased with the win in the cup. It was a good win in a tight game where it could have gone either way.
“When you go to penalties anything can happen. I’m pleased all the practising paid off.
“I think it’s a wonderful tournament. We are very pleased to have reached the fourth round, so can we win one more game to write history? Of course, we’re interested in doing that.”
Baggies boss Slaven Bilic said: “We’re very disappointed with the result, we deserved to go through. It was a very good game between two rivals last year.”
- 20IvanovicSubstituted forO’Sheaat 59′minutesBooked at 88mins
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- Darren England