Jamie Moore, fresh from his win on Sire De Grugy in the Queen Mother Champion Chase at Cheltenham, steered the outsider to a famous victory despite a scare on the run-in when his mount spooked and jinked to his right.
The partnership was soon back intact to record a length-and-a-half verdict over last year's winner Godsmejudge (16-1), with Trustan Times (10-1) just a neck back in third and Merry King (16-1) fourth.
Pembrokeshire-based Bowen said: "He'll be aimed at the Crabbie's Grand National next season. That's the long-term plan … He saw plenty of daylight today and that's how he enjoys it.
"He got to the front too soon, but there was nothing he could do about it and I have a lot of faith in Jamie. He was in the best form we've ever had him.
"Luckily we've got Ffos Las up the road and he had a racecourse gallop there and he was absolutely spot on for today."
Moore said: "I hit the front soon enough, but you know Peter's horses are going to run to the line. Peter told me he had him spot on, but twice up the run-in he spooked at boards or something. I honestly nearly fell off twice and thank God I didn't."
Alan King was proud of the performance of Godsmejudge: "We said all the way through it's been a very difficult preparation," he said. "He's only just coming back and that was a mighty run. He'll have a summer out and regroup for next year."
The veteran Tidal Bay finished seventh after his early exit from the Grand National a week earlier. Paul Nicholls said there were no plans to retire the 13-year-old.
"He will definitely stay in training next season, as long as he is fit and well," he said. "He has run a good race, the ground was probably just against him a bit."
Cockney Sparrow (12-1) sprang a surprise under 7lb claimer Dean Pratt to floor My Tent Or Yours in the QTS Scottish Champion Hurdle. The John Quinn-trained mare came with a devastating late burst to beat Court Minstrel by two-and-a-quarter lengths, with top-weight and Champion Hurdle runner-up My Tent Or Yours another length-and-three-quarters away in third.
"We were going to keep her for the Grade One mares' race at Punchestown, but it was six weeks away after Cheltenham so we came here first," said Quinn. "She's a good ground animal so I'll keep her going until the autumn."
Nicky Henderson, trainer of My Tent Or Yours, had used a hood on his free-going seven-year-old but said: "It was disappointing. The hood didn't seem to help him and we'll give him a break now."
The Nicky Richards-trained Eduard (7-4) brushed aside hot favourite Valdez to be 20-length winner of the Arcadia Consulting William Dickie and Mary Robertson Future Champion Novices' Chase under Brian Harding.
"He's done everything we've asked of him and I wasn't surprised at the way he's won today," said Richards. "Next season we may give him a run in a little race, possibly at Carlisle, and then perhaps have a run in the Old Roan at Aintree."
Although out of luck in the big race, Nicholls chalked up a double. Favourite Silsol, ridden by Jack Sherwood, claimed the Clyde And Solway Systems Limited Racing Excellence "Hands and Heels" Finale Handicap Hurdle by 14 lengths.
Brother Du Berlais (5-1) took the Ayrshire Hospice Making Today Matter Handicap Hurdle by three-and-a-quarter lengths from Rumble Of Thunder under Sam Twiston-Davies.
Nicholls said: "We had this race in mind for a while. It looked a nice race for him and he has gone and done it well."
Trainer Alistair Whillans and his conditional jockey son Ewan got on the scoreboard with 7-2 favourite Samstown in the Weatherbys Private Banking Novices' Handicap Chase.
Whillans senior said: "He's had to run on bad ground through the winter so he appreciated better conditions today."