Japan's Kei Nishikori defeated 5^th seeded Milos Raonic in five grueling sets to advance to his first quarter-finals at the U.S. Open in Flushing Meadows New York early Tuesday.

The 10^th seeded Nishikori won a historical battle 4-6 7(7)-6(4) 6(6)-7(8) 7-5 6-4 that lasted four hours and 19 minutes against Canadian Raonic.

Like Us on Facebook

The longest match in the tournament's history was achieved by no less than Nishikori's Coach, Michael Chang, who lost the battle in the semi-finals in 1992 against Stefan Edberg who eventually won the event.

The time registered was five hours and 29 minutes.

The 24-year-old Nishikori has beaten the hard-hitting Raonic before so it's not surprising that he won again, but what's interesting is that the Canadian served out 35 aces and 86 winners but still lost the match.

This is partly due to the 72 unforced errors that the 23-year-old Roanic committed in the entire match.

"I wish I could have been more efficient in many aspects, like my serves," Raonic said. "I was losing my serve too many times, especially at the beginning of the match."

This was partially due to Nishikori's impressive service returns and baseline play that made Raonic fall back outside the lines, which might be attributed to Chang's teachings.

"Then I felt he got a little over me and I was playing to stay alive," Raonic added.

But after four hours of play, both players were showing signs of fatigue but kept fighting.

 "He had a great serve," Nishikori said. "I just tried play one point at a time and keep fighting."

Raonic is the last of the Canadian tennis players in the tournament as Eugenie Bouchard was also defeated Monday by Ekaterina Makarova in straight sets.

Nishikori will face third-seed Stan Wawrinka in the quarters that defeated Spaniard Tommy Robredo in four sets also on Monday.

TagsMilos Raonic, Kei Nishikori, Michanel Chang, Stan Wawrinka