Champ returned to form in style as he landed the Grade One Long Walk Hurdle at Ascot in game fashion for Jonjo O'Neill Jr - who bagged his first top-level race - and Nicky Henderson.
The enigmatic nine-year-old always travelled smoothly for JP McManus, picking up the running around the final bend and looked likely to pull away in style.
But Thyme Hill - who bounced back from a disappointing run in France - flew home under Tom O'Brien, before Champ pulled out a little more to win by just under two lengths at the finish.
Paisley Park stayed on to finish third, with Thomas Darby back in fourth and Ronald Pump in fifth.
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Jockey Jonjo O'Neill Jr said after the race: "Just to get one winner at Ascot these days is great but to ride Champ in a Grade One for Nicky Henderson and JP, it doesn't get much better than that.
"I was going a bit too easy and needed Ronald Pump to take me into the straight a bit further.
"I knew he was a very good stayer as he won the RSA so I didn't do a lot until Tom [O'Brien] got to me and he [Champ] pulled out a little bit more.
"I've had three bad injuries this year and it's taken a while to get going. It only takes one horse to get you back."
Trainer Nicky Henderson added: "Things haven't always gone his way. We always thought he would win a Gold Cup and we always thought he was special.
"He didn't get that name for no reason! It just seemed the obvious thing to do for his confidence to have a run over hurdles.
"This was the only race you could run him in."
Annsam claims Silver success
Trainer Evan Williams landed Listed success as Annsam took the Silver Cup Handicap Chase under jockey Adam Wedge.
The six-year-old, who had finished in the places on two starts over hurdles this season, enjoyed his return to the larger obtacles, beating the JP McManus-owned duo Phoenix Way and Jerrysback.
Earlier on the card, Palmers Hill stayed on best of all for the Jonjo O'Neill team to land the Howden Handicap Chase, seeing off the strong-travelling Diego Du Charmil and Harry Cobden.
The second - trained by Paul Nicholls - looked the winner in over the penultimate fence, but looked to be paddling in the closing stages and was eventually picked up by Palmers Hill, ridden by Jonjo Jr, who won by just under 10 lengths at the finish.
Knight In Dubai made the early running under Harry Skelton and eventually finished a well-beaten third.
L'homme Presse rewarded favourite backers in the Howden Graduation Chase, running out an impressive winner and remaining unbeaten over fences for Charlie Deutsch and the in-form Venetia Williams team.
Second favourite Pencilfulloflead made the task easier for the market leader when falling, with former Challow Hurdle winner Messire Des Obeaux performing wonders to jump over the loose horse and complete.
But the eventual winner was always travelling best of all, with jockey Deutsch nudging his mount clear to win by 13 lengths from Legends Ryde, who jumped markedly out to his left throughout for Page Fuller.
Deutsch said after the race: "He had a race at Exeter and I thought this would be a bit of a step but I didn't think it would be that easy.
"He was taking lengths of other horses - I thought at three out we might as well go on and he was taking me there.
"Once they start jumping one way they tend to go there but it was all very straightforward. He was a joy to ride."
Ardhill landed an extraordinary gamble in the opening race of the card, being backed into 4/1 favourite and landing the odds in dominant fashion for Gordon Elliott and Adam Wedge.
The six-year-old gelding was held up in midfield before scything his way through the field, with a loose horse seemingly the sole danger between the final two flights but caused no trouble as Wedge guided his mount home to win by seven-and-a-half lengths.
Imphal continued his good form, finishing second for Gary Moore who also had the third with Next Left, ridden by Jonjo O'Neill Jr.
In the final race on the card, Tritonic landed the Betfair Exchange Trophy for Adrian Heskin and Alan King.