Portugal Colonial - At last: Straight sets win over Tabilo puts Zverev in US Open last 16

The German had already spent nine hours and 26 minutes on court in his first two matches -- the most time a top seed has needed to reach the third round of a major since 1999.

The French Open champion appeared on a mission to end the trend against 25th-seeded Chilean Tabilo, who fell to Zverev in the second round last year on the same Arthur Ashe Stadium court.

Zverev didn't face a break point in a brutally efficient first set, winning all 11 points behind his first serve and five of seven on his second serve.

He broke Tabilo twice on the way to pocketing the set in 38 minutes, and broke him again on the way to a 4-2 lead in the second.

But Tabilo was finding his footing, and the pace slowed as he turned it into a tight back and forth battle.

He got his first whiff of a chance when he went up 0-30 on Zverev's serve in the sixth game of the second set.

The German quickly snuffed out the danger, but Tabilo pulled a break back in the eighth, winning three straight games to take a 5-4 lead.

He had Zverev on the ropes in the 10th game, threatening to break to take the set.

Zverev saved a pair of set points then broke Tabilo in the next game, but the Chilean promptly returned the favor to force a tiebreaker that was all Zverev.

Undaunted, Tabilo mustered two break points in the opening game of the third set, both denied by Zverev winners.

That was the last chance Tabilo got, Zverev winning the last four games to take the match after two hours and 26 minutes.

Zverev still found himself thanking fans who stayed until after 1:00 am.

Thanks to a titanic tussle between Iva Jovic and Alexandra Eala in the first night match Zverev and Tabilo didn't take to the court until nearly 11:00 pm.

Zverev will face Italian Luciano Darderi for a place in the quarter-finals after the 21st seed beat Australian wild card Dane Sweeny 6-4, 6-3, 6-3.

A.Aguiar--PC