Hamburg (Germany), Jul 18 (IANS): While he continues to manage pain in his left knee resulting from a nasty fall at Wimbledon, Germany's Alexander Zverev enjoyed a comfortable first-round win at the Hamburg Open, defeating Jesper de Jong in straight sets here on Wednesday.

The World No. 4, who overextended his knee during a slip and fell in a third-round win over Cameron Norrie at the grass-court major, dropped just seven points on his first serve and did not face a break point in a 6-2, 6-2 win over Jesper de Jong.

"I was still unsure this morning if I was going to play or not and during the warm-up, I was in quite a lot of pain," said Zverev, who has a bone oedema and tear in the capsule of his knee.

"But somehow when I step on this court it disappears a little bit when the adrenaline gets going," he was quoted as saying by the ATP Tour in a report on Wednesday.

"I have an injury where I know where I stand, and it will take time to heal. It won't heal in the next few days, it will take weeks and it's up to me if I am going to play like that or not," he said.

Making a successful transition from his fourth-round run at Wimbledon to the clay on home soil in Germany, the defending champion collected his 41st match win of the season and improved to 12-1 in first-round outings this season.