By Amy Tennery
NEW YORK (Reuters) - Daniil Medvedev fought off cramps under the piercing sun to beat Hugo Dellien 6-3 7-5 5-7 6-3 and clinch a third-round berth at the U.S. Open on Thursday, continuing his hot run of form over the last month.
The 23-year-old fired down 17 aces and 55 winners, dominating the shorter rallies, but struggled late in the third set, handing Dellien a break and 6-5 lead with a double fault.
After returning Dellien's serve at set point, Medvedev wandered off the side of the court, raised his arms and flicked his hands in resignation as the 84th ranked Bolivian fired off a forehand winner.
The fifth seed, who arrived in Flushing Meadows on a high after winning his first Masters series title at Cincinnati, said afterwards that he had struggled with cramps during the latter part of the match.
"I honestly don’t know how I (won)," Medvedev said. "At one moment in the match I thought ‘Okay, I cannot move anymore'."
Medvedev also cramped up when he was on the brink of sealing the title in the Cincinnati final against David Goffin two weeks ago, on that occasion reeling off a string of aces to secure the win.
The Russian said he was optimistic that his body would be able to bounce back in time for his match on Friday against unseeded Spaniard Feliciano Lopez.
"I said straight after the match, cramps is not an injury. You just need to relax, to have a good sleep," said Medvedev.
"I mean, we're sportsmen. Your body reacts good the next day.
"At this moment I'm tired, but looking forward for tomorrow I think it should be okay."
(Reporting by Amy Tennery; Editing by Ken Ferris/Nick Mulvenney)