NEW YORK (Reuters) - Unseeded Canadian Vasek Pospisil pulled off another stunning upset at the U.S. Open when he knocked out Spain's eighth seed Roberto Bautista Agut 7-5 2-6 4-6 6-3 6-2 in the third round on Saturday.
Pospisil, who eliminated fellow Canadian and 25th seed Milos Raonic in the second round, has already spent nearly 10 hours on court in three matches at Flushing Meadows after this contest lasted three hours and 40 minutes.
The 30-year-old advanced to the last-16 in Flushing Meadows for the first time in his career after smashing 71 winners and 19 aces past Bautista Agut.
"I worked really hard, just thrilled to be here," Pospisil said in his on-court interview. "If you can get wins like this against top players in the sport on a huge stage like this, that's a really big deal.
"I was just trying to dictate play... play aggressive and go for the win with no doubts and no regrets. That's the mentality I had all the way through to the end."
The opening set went with serve until Bautista Agut was forced to save two set points at 5-4 and the Spaniard held serve well to save both.
But Pospisil roared right back at 6-5 to break, converting his third set point with an resounding cross court forehand winner.
Pospisil lost his focus in the second set after an argument with umpire over the serve clock winding down while he looked for his towel and that was just the opening Bautista Agut needed to break the Canadian twice.
Bautista Agut carried that momentum into third set as well and even though Pospisil fired more aces and winners, it was the Spaniard who converted the lone break point in the set.
Pospisil requested a medical time out early in the fourth set to have his right leg strapped up and the break seemed to rejuvenate the Canadian who fired 20 winners in the set to Bautista Agut's one and take it to a decider.
The underdog found a new lease of life in the decider, breaking Bautista Agut at 1-1 before converting another to seal the tie and book his spot in the next round where he will play Australian 21st seed Alex de Minaur.
(Reporting by Rohith Nair in Bengaluru; Editing by Ken Ferris and Pritha Sarkar)