Sutton boss Matt Gray was delighted to make it third time lucky in the Carabao Cup after beating Cambridge 6-5 on penalties.
The south-west London club had failed in their two previous attempts to win a match in the competition.
And they came from behind twice to force penalties as goals from Harry Smith and Harry Beautyman cancelled out Fejiri Okenabirhie’s brace at Gander Green Lane.
“It’s nice to be in the hat for the second round after the last couple of years,” admitted Gray.
“It’s the first time we’ve won a League Cup game. The Premier League boys come in now so it would be great to get one.
“It’s nice to get another win on penalties and make sure we got through to the next round.
“I was pleased with a hell of a lot from the game.
“I’ve really noticed the team spirit ever since our pre-season trip. We showed great character to come from behind twice and I’m really pleased with the spirit in the group.
“We don’t practice the specific penalties. Everyone knows to pick their spot and commit to the penalty.”
Cambridge’s George Thomas and Sutton’s Ben Goodliffe both missed to take the shoot-out to sudden death, where Jack Rose – a half-time substitute for Sutton’s starting keeper Steve Arnold – made the decisive save from Harrison Dunk.
Deflated Cambridge boss Mark Bonner said: “It’s disappointing to go out on penalties.
“When you get the upper hand in penalties you hope you’ll see that home, but it wasn’t to be.
“That Wembley dream’s over this year, but we’ll get ourselves ready for a big week ahead.
“It’s a successful night for us with all the changes we made. We managed to get some good minutes into players who didn’t get to play on Saturday.
“We got a few more minutes into some than we would have liked because the game went on for three hours.”