Roger Varian's juvenile had been placed on each of his three previous appearances, most recently finishing third behind Dream Today - who runs in Saturday's Champagne Stakes - in last month's Convivial Maiden at York.
Laugh A Minute was a 12-1 shot for this 22-runner contest and powered home on the far side of the track under Andrea Atzeni to score a shade comfortably by a length and a quarter.
Danzan was a clear second ahead of Alba Power in third. Great Prospector, the 7-2 favourite, was fourth.
Atzeni said: "We've always liked him and he's always worked like a good horse.
"Last time he probably didn't quite stay seven furlongs and he was caught wide all the way around.
"He's a horse with a real good turn of foot. He travelled beautifully through the race and picked up well. He'll be a better three-year-old and he has a lot of speed."
Ellthea outclassed her rivals in the EBF British Stallion Studs "Carrie Red" Fillies' Nursery.
Karl Burke's juvenile looked an exciting prospect after winning on her second start at Carlisle, but having since come up short at Listed and Group Three level, she was switched to handicap company for her latest assignment.
The 8-1 shot travelled smoothly under apprentice Clifford Lee and drew clear in impressive fashion in the final furlong to register a three-and-three-quarter-length success.
Clubbable, the 7-4 favourite, was under pressure from an early stage, but boxed on to fill the runner-up spot.
Lee said: "She gave me everything. Her last couple of runs were a bit disappointing, but she kept coming in season. She is back to her normal self there and has won nicely."
Burke, who also won the May Hill with Laurens, said: "She's been in season basically all year, at home and at the races, and consequently wasn't running her race.
"The girl who looks after her told me as soon as I got her today that this is the first time since Carlisle she's not been in season and obviously that's made the difference.
"We've always thought she was good. That was very impressive and there's no reason she won't train on. There's a Listed race in Ireland for her we'll go for next and if that goes well we could take her back to France."
Buccaneers Vault was a clear-cut winner of the DFS Silk Series Lady Riders' Handicap.
The six-furlong contest opened day two of the St Leger Festival on Town Moor, with a mixture of amateur and female riders doing battle over the straight six furlongs.
The Paul Midgley-trained Buccaneers Vault was a 9-1 chance in the hands of Georgia Cox and was waited with while stablemate Related set the pace.
Cox's mount quickened up smartly to take the lead inside the final two furlongs and though 4-1 favourite Kenny The Captain got rolling late, Buccaneers Vault held him at bay by a length.
"He was very straightforward to ride and took me into the race really well," said the winning jockey.
"Mr Midgley was very confident about his chances and actually told me he'd win, so full credit to him.
"I was wary there was a lot of pace in the race and he (Midgley) told me just to sit where the horse was happy.
"He was a bit fresh out of the stalls and we met a little bit of trouble, but it didn't seem to bother him."
Midgley, based at Westow near York, said: "It's nice to have a winner this week, it's a big week.
"It was a good pot and he's just about paid for himself. We got him from Newmarket sales from Michael Dods.
"He (Buccaneers Vault) is a lovely person and a very straightforward ride. A race like this probably suits him as there was plenty of speed on slow ground and they just came back to him. All he does is plug away.
"He's been pretty consistent all year. The only thing he hasn't done is win, but he's gone and won well today, which is great."