NEW YORK, Sept 9 (Reuters) - Alexander Zverev took another big step towards a second Grand Slam title by beating Dutchman Botic van de Zandschulp 6-2 7-5 6-1 to reach the U.S. Open semi-finals, where the German will take on Karen Khachanov.
The 29-year-old French Open champion got off to a slow start in his campaign at Flushing Meadows but has steadily found his range.
"I think you saw in the first two rounds, I really didn't play well," Zverev said.
"In other tournaments I would be out in the first round, but here I can fight back and play best of five sets, play 4-1/2 hours. I've started playing better throughout the tournament and I'm definitely happy to be in the semi-finals here."
The German has reached the semi-finals at all four majors this year and is the only Grand Slam winner left standing in the men's draw.
"I don't take it for granted at all," Zverev said.
"I know it can change in a heartbeat in tennis. I think confidence is something that is incredibly important but also can go away quite quickly."
Zverev was far from steady on serve early on at Arthur Ashe Stadium, coughing up five double faults in an erratic start, but van de Zandschulp leaked forehand errors to allow the top seed to break in the fifth game and then take the first set.
Van de Zandschulp regrouped in the second set and came close to levelling the contest, but Zverev absorbed the pressure and reeled off three games in a row towards the end as the momentum swung firmly in the German's favour.
Zverev, the 2020 runner-up, fired an overhead smash to break early in the third set and cruised home from there to reach his third semi-final in New York.
With 23 Grand Slam match wins this year, Zverev surpassed Boris Becker's German men's record of 22 from 1989.
He next faces Russian Khachanov in a rematch of their gold medal showdown at the Tokyo Olympics in 2021.
(Reporting by Shrivathsa Sridhar in New York; Additional reporting by Janina Nuno Rios and Chiranjit Ojha in Bengaluru; Editing by Peter Rutherford)
