WHAT HAPPENED: No. 9 seed Marin Cilic appeared to be cruising to victory in his quarterfinal against No. 19 seed Jo-Wilfried Tsonga, but day turned into night, as Cilic ended up needing five sets to prevail in one of the longest matches of the tournament, 6-4, 6-4, 3-6, 6-7, 6-4.
Both players had numerous chances to break serve throughout the first set but were unable to capitalize on these early opportunities. A long deuce game on Tsonga's serve at 4-4 finally led to a forehand error from the Frenchman that gave Cilic the initial break of serve. He then comfortably closed out the set on his serve in the very next game.
Tsonga began to start spraying his forehand in the second set and finished the set with more unforced errors (14) than winners (nine). A lone break of serve at 2-2 was all Cilic needed. He didn't face a single break point and easily held serve once again at 5-4 to take a commanding two-set lead.
But just as it appeared that Cilic would run away with the match, Tsonga raised his level at the most crucial moments of the match for him. He earned two break-point opportunities with Cilic serving at 3-4 and converted on the second by forcing a forehand error from the defending champion. Tsonga then held serve in the next game to take the third set and close the gap considerably.
Both players continued to trade service holds in the fourth set. Tsonga found himself a point away from defeat on several occasions but saved two set points serving at 4-5 and another at 5-6 to force a tiebreak. But at 2-2, a double fault from Cilic gave Tsonga the all-important mini-break. Tsonga rode the momentum through the rest of the tiebreak and fired a service winner on his first set point to send the match into a deciding fifth set.
The fans inside Arthur Ashe Stadium began to start buzzing at the possibility of a come-from-behind victory from Tsonga, but Cilic silenced them by breaking Tsonga at love to take a 4-2 lead. The defending champion blinked again while serving at 5-4 with a double fault on his fourth match point but finally converted on his fifth opportunity to move into the semifinals. The match was just one minute shy of the four-hour mark.
"It was a big mental battle, especially after losing the fourth set," said Cilic. "But I still felt like I was playing well and didn't back off from my game plan."
WHAT IT MEANS: Cilic is now 5-3 against Tsonga with this win, and it also marks his fourth consecutive victory over the Frenchman. The win moves Cilic into his third semifinal of the year. Although his 18-13 record coming into the US Open shows that 2015 has been a relatively lean year for Cilic, he's peaking at exactly the right time. The quarterfinals was the moment at last year's US Open when Cilic came alive by defeating Tomas Berdych, Roger Federer and Kei Nishikori without the loss of a set.
Next up for Cilic is either No. 1 seed Novak Djokovic or No. 18 Feliciano Lopez. Cilic has yet to beat Djokovic in 13 previous career meetings but did extend him to five sets in the 2014 Wimbledon quarterfinals. He's a far more favorable 3-2 against Lopez and has won both of their previous hard-court meetings.
However, Cilic was also a significant underdog against world No. 2 Roger Federer in the semifinals of last year's US Open before defeating him in straight sets. The Croat plays his very best tennis in New York, and this is arguably the best possible location for him to reverse the losing streak.
THE QUESTION: Do you think that Cilic can return to the final or win this year's US Open?