Flemenstar's lack of fitness counted against him on his Navan comeback as he was no match for Felix Yonger in the Grade Two Webster Cup Chase.
Tony Martin's three-times Grade One winner was having his first start for 503 days and made most of the running in the hands of Keith Donoghue.
He still held a slight advantage after the third-last fence, but the tank emptied and the race-fit Felix Yonger took control as Flemenstar faded out.
Felix Yonger, trained by Willie Mullins and ridden by Ruby Walsh, made a bit of a hash of the final fence, but the 11-10 favourite still had three and three-quarters of a length in hand of Argocat at the line.
Martin said: "He jumped great and it was only from the second-last that he got very tired. Flemenstar gave him (Donoghue) a great ride until two out and hopefully he's all right in the morning."
Felix Yonger could now run at the Punchestown Festival.
Mullins said: "I was very happy to see him going on that ground. It was very sticky, heavy ground and I didn't think he'd go on it. The fact that he's won over two and a half miles on that means we could open up in trip more on better ground.
"I'm not sure where he'll go next, but he'll get an entry for the Champion Chase at Punchestown. He's improving."
Meanwhile, Gabrial showed a touch of class and the heart for a battle to win the Betway Lincoln at Doncaster.
Richard Fahey's streetwise, but often unpredictable six-year-old was delivered with a precise challenge by Tony Hamilton to take the first major prize of the Flat turf season at odds of 12-1.
Mondialiste was a determined foe for the David O'Meara team, but once that rival was subdued, Gabrial was in pole position, eventually winning by a neck.
It was a second Lincoln in four years for Hamilton, Fahey and owner, Dr Marwan Koukash, and the latter was over the moon.
"When I started off in racing I always wanted to win the big handicaps, Cesarewitch, Ayr Gold Cup and the Lincoln," said Koukash. "When I first met Richard I asked what race he would like to win the most and he said it was this one. Now we've done it twice so I'm delighted."
Fahey said: "They raced in a very tight pack and I wasn't sure he was going to get out in time.
"That's the first time I've ever seen him really pin his ears back and have a real go, as he's a bit of a character. Tony said he always felt like he was going to win.
"He's a Listed winner and, while I doubt he's getting better, we'll hatch a plan and see where we go, I presume it will be Chester."
At which point, Koukash responded: "He'll go to the Huxley Stakes over 10 furlongs at Chester."
Sunday Indo Sport