Paul Townend© Photo Healy Racing
Paul Townend struck at Cheltenham when Anteros sprang a 20-1 surprise in the Regulatory Finance Solutions Handicap Hurdle.
Corrin Wood put in a brave effort in trying to make all and was still in front coming to the last flight in the Listed heat, but Anteros was cantering for Townend having made stealthy progress from well off the pace.
He put in an excellent leap at the last and accelerated away up the hill to win by seven lengths.
Trainer Sophie Leech said: "I always thought he could win a nice handicap like this as he's always been a nice horse.
"There's so much work that goes into him as he's never been easy to train. He was very keen as a young horse and he's just very late maturing. Every summer on his back he's done better physically and matured mentally.
"He just needs to be produced at the right moment as he doesn't find much off the bridle, but it worked out great today."
Defi Du Seuil staked an early claim for Festival honours with an impressive performance to take the JCB Triumph Trial Juvenile Hurdle.
The Philip Hobbs-trained three-year-old followed up his debut success over jumps at Ffos Los in some style under Barry Geraghty.
East Indies and Red Hot Chilly made most of the running to three out, where Defi Du Seuil and Dino Velvet cruised up to take closer order. The latter came down at the final flight when holding every chance and that left Defi Du Seuil to win snugly by a length and three-quarters from Diable De Sivola.
Hobbs said: "He's a lovely horse at home and everything he does is really nice. It's a big relief to see him come here and do that today. He did it very well at Ffos Las. It was a very minor race there, but we were hoping he'd do that today. He's a very nice prospect for the future.
"He's done everything well. He always jumps well and has a really good attitude and softer ground will be no problem to him, he's very pleased. Barry was very pleased. I imagine he'll run somewhere before the Festival, but I'm not sure where he might go."
The ex-Irish grey Viconte Du Noyer (20-1) won a dramatic race for the extended three mile three handicap chase to complete a quick double for the Colin Tizzard stable after the earlier triumph of Thistlecrack.
