Bobs Worth bounced back from a disappointing seasonal reappearance to land the Grade One Lexus Chase at Leopardstown.
Winner of last season's Cheltenham Gold Cup, Bobs Worth could finish only sixth behind Cue Card in the Betfair Chase at Haydock on his return last month, but he stepped up significantly on that effort to win the three-mile feature.
First Lieutenant jumped the last in the lead but Bobs Worth (11-4 joint-favourite) found plenty for Barry Geraghty on the run in to win by a length and a half, with Rubi Ball back in third.
Ruby Walsh set out to make all on Rubi Ball with First Lieutenant, Bobs Worth and his fellow joint-favourite Sir Des Champs sitting on his heels through the early stages.
With four fences to jump, there were a handful of contenders queuing up in behind to challenge Rubi Ball, with First Lieutenant putting in a couple of excellent leaps to put himself on terms with the leader.
However, Geraghty switched Bobs Worth to the outside turning for home and he found plenty for pressure on the run to the last.
He continued to dig deep all the way to the line and his triumph puts Bobs Worth right back into the Betfred Cheltenham Gold Cup reckoning.
Betvictor and Paddy Power both now make him the 5-2 favourite to retain his title.
Henderson said: "I would have given anything to take him out two days ago. With the ground and the weather, I wasn't that happy with him, but the horse never stops surprising you.
"You have to be handier round here than you would normally be. When I saw Barry angle him out, I said to myself obviously he thinks he'll get there. We all know he finishes his races, except of course for Haydock.
"It's only five or six weeks since he got thumped into the ground there so to come back from that is great.
"I wanted to wait for the Argento Chase (at Cheltenham on January 25) but Barry was keen to come here. He believed he would get better ground here than anywhere in England.
"If we waited for the Argento and it turned up heavy, we'd only have five or six weeks before Cheltenham. This was the right race for him but conditions weren't perfect.
"He picked himself up after a horror run and he put himself back at the front of the ball game. We know he loves Cheltenham,
"He had a hard race there and whether he runs again or not (before the Gold Cup), I don't know, but my gut says no.
"We came here hoping he would respectably and to win is a bonus. After Haydock, it's great to get him back."
Mouse Morris, trainer of First Lieutenant was satisfied with his charge, adding: "He probably wants a stiffer track but there's no excuses."
His rider, David Casey, added: "He gave me a brilliant ride. He jumped like a buck and quickened well going to the last.
"I thought I might have had it and the horse gave me everything, but the winner's a good horse and we're unlucky to have met him."