Rafael Nadal Beats Karen Khachanov to Advance to 4th Round of 2018 US Open

Rafael Nadal's quest to defend his U.S. Open title is still alive as he survived an extraordinary test from Karen Khachanov in the third round in New York on Friday. 

Nadal persevered in the hard-fought match in four sets, 5-7, 7-5, 7-6 (7), 7-6 (3).

The two had previously met on the court four times, with Nadal coming out on top each time. But this latest showdown was on a different level than any of their previous matchups.

In fact, Khachanov had never even taken a set from the top-ranked player in the world before Friday. They had met twice before in 2018, most recently in the semifinals of the ATP World Tour Masters 1000 Canada in Toronto earlier this month.

This time around, though, Khachanov made it clear right from the start that Nadal would not be able to breeze on through to the fourth round. The 22-year-old Russian took the first set, 7-5, behind the strength of eight aces and 23 winners, helping neutralize 15 unforced errors.

Just like that, he captured his first set against Nadal in 10 career attempts.

The two continued their hard-fought battle into the second set. However, a 12-minute weather delay forced them to pause the action at 5-5 as the roof was closed. When play resumed, it was Nadal who came out stronger. The 32-year-old won the first two games after the delay to take the second set, 7-5.

From there, it turned into a best-of-three match.

As tight as the first two sets were, the third set was even more intense. Each player won 42 points in the set, and a number of stats (double faults, winners, unforced errors) were also nearly identical. The two went deep into a tiebreaker as neither was able to pull away.

Ultimately, though, the three-time U.S. Open champ was able to outlast his opponent:

Afterward, Nadal expressed the importance of winning the 39-shot rally in the tiebreaker, via George Bellshaw of Metro UK:

By the time the third set had wrapped up, the match was nearly three-and-a-half hours old.

It should come as no surprise that the fourth set also went down to the wire. Nadal seemingly was in control for the majority of the set, but Khachanov never gave up and battled back. He even held a 6-5 lead, but this set was also destined for a tiebreaker.

"

Rafael Nadal advances after the longest match of the US Open thus far ... and this, one of the most dazzling points of the tournament  pic.twitter.com/aGaWtgvSkT

— SportsCenter (@SportsCenter) August 31, 2018"

The second tiebreaker of the match was the first time either player was able to get some breathing room, with Nadal jumping out to a 6-1 advantage. Khachanov once again fought until the end. 

In the end, this match produced some incredible numbers. Four hours and 23 minutes, the longest match of this year's tournament to date. A 162-156 Nadal advantage in points. A 22-0 Khachanov edge in aces. Both competitors covered more than 16,000 feet of ground, according to the official website of the U.S. Open.

Khachanov gave a valiant effort, but he learned that taking down the No. 1 player in the world is no easy task. There was very little separation between the two pros on this day. Unfortunately for Khachanov, he just couldn't find a way to finish Nadal off in any of the ensuing sets.

Winning a match like this would be impressive regardless of the situation, but considering Nadal was playing through a knee injury, he deserves even more credit for finding a way to survive and advance. 

Nadal was in danger of being eliminated in the third round of the U.S. Open for the second time in four years, but he has now advanced to the fourth round for the third consecutive year. This was the furthest Khachanov has made it in New York.

Nadal will face Nikoloz Basilashvili in the fourth round. Basilashvilli topped Guido Pella 6-3, 6-4, 1-6, 7-6 (4) on Friday.