NEW YORK (Reuters) - Vasek Pospisil picked the ideal time to secure his first win of the season as the Canadian upset Russian ninth seed Karen Khachanov 4-6 7-5 7-5 4-6 6-3 on Tuesday to reach the second round of the U.S. Open.
Pospisil, who has fallen to 216th in the world rankings after having back surgery in January that sidelined him until Wimbledon, fired 15 aces and broke Khachanov four times during the near four-hour encounter.
The 29-year-old Canadian, who is in the main draw with a protected ranking, said he entered the match with a plan to be aggressive against Khachanov.
"Obviously Karen hits a really big ball. When he has time on the stroke, he's extremely dangerous," said Pospisil, whose previous win on the ATP Tour came last October.
"I just tried to really go for my forehand and tried to serve well, which I did for the most part. It was a physical match there at the end. I'm just glad I pulled through."
The former world No. 25 converted four of his six break point chances while Khachanov could take advantage of only three of his 12.
Pospisil, who has never advanced past the second round in New York, will next face unseeded Tennys Sandgren after the American beat Frenchman Jo-Wilfried Tsonga earlier on Tuesday.
(Editing by Greg Stutchbury/Peter Rutherford)
