WATCH: Nadal reacts to pain-free win over Duckworth at Australian Open

WATCH: Nadal reacts to pain-free win over Duckworth at Australian Open

The world No. 2 didn't play his best, but he still won in straight sets.

MELBOURNE, Australia (AP) — Rafael Nadal has missed a lot of tennis since last September. He hasn't missed a beat.

The No. 2-seeded Nadal had a 6-4, 6-3, 7-5 win over Australian wild-card entry James Duckworth on Monday in the first round of the Australian Open, his first match back on Rod Laver Arena since he had to retire during his quarterfinal match last year.

The 17-time major winner hasn't played since retiring from his semifinal at the U.S. Open because of a knee injury, and then had surgery on his right ankle in November. He also withdrew from a tune-up tournament in Brisbane because of a muscle strain in his thigh, mainly as a precaution, to ensure he's fit for the season-opening major.

"Not easy to come back after a lot of months of competition, especially against a player playing super aggressive every shot," Nadal said. "It's very difficult to start after an injury — I know it very well.

"So that's an important victory because is the first victory since a while, and at the same time, because that gives me the chance to be on court again."

Wearing a sleeveless top, he showed no signs of any issues against Duckworth. His only hiccup came when he served for the match in the ninth game of the third set and was broken. He returned the favor quickly, though, to seal his spot in the second round.

Nadal has only lost twice in the first round at Grand Slams — to Steve Darcis at 2013 Wimbledon, and to Fernando Verdasco here in 2016.