Rising tennis star Alexander Zverev has won his first ATP title on an outdoor hard court, claiming the Washington Open against veteran South African Kevin Anderson.

The eighth-ranked Zverev easily dispatched Anderson 6-4 6-4 on Sunday to win the Washington event for his fourth ATP title of the year, matching Rafael Nadal’s victory total. Only Roger Federer has more titles this season, with five.

Zverev didn’t lose a set after the opening match of his tournament against Australian Jordan Thompson and grew stronger as the event went on, having little trouble with the hot and humid conditions in Washington or the late nights brought on by rain delays.

Anderson, 31, came in to the final with a tournament-best 62 aces, but his German opponent got enough first serves back to give himself ample break opportunities. Zverev broke Anderson early in each set and never faced a break point on his own serve.

“It was a great match,” the 20-year-old said.

“I felt unbelievable starting from the quarter-finals and from then it got better and better every match I played.”

Zverev’s previous titles this year came at a Masters event on clay in Rome, along with wins on clay in Munich and on indoor hard courts in Montpellier, France.

He said the next goal is to go deeper into the grand slams, ahead of the US Open starting later in August.

“I’ve lost in five sets against Rafa, five sets against (Milos) Raonic,” he said.

“At some stage I want to win those kind of matches and get further in grand slams.

“The best I’ve done is fourth round. I know I still have to improve a lot to be able to go far in the big tournaments.”