BEIJING, China (AFP) — Carlos Alcaraz roared back from a set down to beat world No. 1 Jannik Sinner in a thriller and win his first China Open title on Wednesday.

The four-time Grand Slam champion edged a captivating final 6-7 (6/8), 6-4, 7-6 (7/3) for his fourth ATP crown of the year and 16th overall.

The Spaniard, who is set to return to number two in the world behind Sinner, was 3-0 down in the final-set tie break only to fight back and win in three hours and 21 minutes.

The longest men’s singles match in China Open history saw Sinner deposed as the Beijing champion after an almighty fight.

Alcaraz called it “a special win” that was even more satisfying in light of his shock second-round exit at the recent US Open.

He hopes it will win the sport more fans.

“When Jannik and I play it’s a good thing for tennis because we always show a really intense match, really close match, great points, great rallies,” he said.

“I think for people who don’t watch tennis, probably thanks to these kinds of matches, they will start to watch tennis or even practice it.”

US Open champion Sinner reached the final in Beijing under fresh scrutiny.

The Italian has admitted to sleepless nights over his doping case, which was reignited at the weekend when the World Anti-Doping Agency (WADA) said it had appealed against a decision to clear him.

He called it one of the toughest matches he had ever played.

“These kinds of matches can really go both ways, but it was not my day,” Sinner said.

“He played better in the important moments, that’s it.”

He added: “Today all three sets, they were very tough physically.”

In front of a packed house, Sinner was first to blink, with second-seeded Alcaraz breaking for a 3-1 lead in the opening set.

The Spaniard held easily for 4-1 and had his opponent rattled.

Alcaraz, 21, served for the set but Sinner grabbed the break back when he needed it most.

Sinner then saved set point on his own serve to force the tie break, and saved another in the tie break before taking the set at his first opportunity when Alcaraz fired long.

It was the first set Alcaraz had dropped all week.

The second set was just as tight.

Both players saw chances come and go but they went with serve until Alcaraz broke for 5-4, before holding to send the final into a third set.

The decider again went to a tie break, where Alcaraz finally prevailed on his first match point.