PIX: Nagal loses to birthday boy Thiem; out of US Open

Second seed Dominic Thiem celebrated his 27th birthday with a commanding 6-3, 6-3, 6-2 victory over India's Sumit Nagal on Thursday to move into the third round of the US Open.

Austrian Thiem, seeking his maiden Grand Slam title, won an overwhelming 74% of his first serve points and fired seven aces past the inexperienced Nagal, breaking him seven times in the two-hour contest.

Thiem, who was runner-up at the Australian Open, has only played five sets at the tournament after first-round opponent Jaume Munar retired.

"It's difficult to say where I stand because I recently played a lot of exhibition matches," said Thiem, who lost his opening match at the Western & Southern Open last week.

"Hopefully, I can get back to the level before we stopped due to the (COVID-19) crisis."

Nagal became the first Indian in seven years to win a singles match at Flushing Meadows on Tuesday but the 23-year-old showed only flashes of brilliance in a one-sided clash at Arthur Ashe Stadium.

Thiem broke Nagal in his first service game and raced into a 3-0 lead before the Indian overcame his sluggish start to go toe-to-toe with the world number three in the longer rallies.

Nagal broke back in a marathon fifth game and held serve to make it 3-3 before Thiem used his first serve as a weapon to wrest back control, sealing the set with an ace.

Following an argument with an official who frowned upon Thiem consuming his energy drink straig from the can, the fired-up Austrian fared better in the second set, converting three break points as Nagal's error count climbed.

The story was the same in the final set when Thiem built a 3-0 lead before Nagal offered stronger resistance, but the result was never in doubt as the Austrian finished the match with 30 winners including some searing backhand returns.

"He's a few levels ahead of me, he's got way more experience and knows how to play better on courts like this," Nagal said. "I was always chasing him.

"I need to start matches with focus and discipline... It's only going to get better with experience, with more matches I play."

Up next for Thiem is 2014 champion Marin Cilic of Croatia who beat Slovakia's Norbert Gombos 6-3, 1-6, 7-6(2), 7-5.