Nadal sails through, Kerber exits from US Open

World number one Rafael Nadal staggered at the beginning but found his way out to advance into next round while Japanese teenager Naomi Osaka stole the headlines by knocking out defending champion Angelique Kerber in the opening round of the US Open which was hit by torrential rain on Tuesday.

Steady rain prompted Open officials to cancel 44 singles matches and postpone completion of 11 others underway when showers halted play.

Nadal began his campaign for a third US Open title with a 7-6 (6), 6-2, 6-2 win against Serbia's Dusan Lajovic.

The 31-year-old Spaniard recovered from 3-5 down in the opening set against the 85th-ranked Lajovic, who has never won a match in New York.

"When I was down in the first set, I just tried to be there as he was playing well and controlling the points," said French Open champion Nadal, who is chasing a 16th major.

"But the end of the first set was very important. I got the break back and after that, everything changed."

German defending champion Angelique Kerber was given a shock first-round exit, losing to Japan's Naomi Osaka 6-3, 6-1.

It took Osaka, ranked 45th in the world, just 64 minutes to send Kerber packing, one year after the German's triumph at Flushing Meadows.

Osaka hit hard from both sides and struck 22 clean winners in the match while Kerber, the first defending champion to lose in the US Open's first round since Svetlana Kuznetsova of Russia in 2005, was just in a different league.

A year ago on the same Arthur Ashe Stadium court, Osaka squandered a 5-1 lead in the final set and lost to American Madison Keys 7-5, 4-6, 7-6(3) in a third-round match.

"When I stepped on the court and I heard all the people and I saw how big the stadium was, I got a little bit freaked out, but I tried to hold it in," the Japanese teenager said.

"I felt the same type of nerves come up 4-1 in this match, so I wanted to tell myself just to keep playing how I was playing and not let the nerves get over me as much as last year," she said.

There's also win for third seed Roger Federer of Switzerland, who defeated Frances Tiafoe of United States in five sets, and in women's side, Karolina Pliskova, who is seeded No. 1, easily advanced by beating Magda Linette of Poland 6-2, 6-1, French Open champion Jelena Ostapenk of Latvia got past Lara Arruabarrena of Spain 6-2, 1-6, 6-1.