It was an up and down match for the two German players, with the veteran pulling out the win over the young gun. It took him nearly three and a half hours, but 31-year-old Philipp Kohlschreiber defeated the youngest player in the top 100 of the Emirates ATP World Rankings in five sets. Alexander Zverev, nicknamed Sascha, is an 18-year-old German player of Russian descent and was the number one junior player between October 2013 and June 2014. 

Set One

Zverev, who had already won three qualifying matches to make his first US Open main draw, took the first set, which lasted 59 minutes, in a tiebreaker. It was a very close set up until the breaker, when the younger player won seven points in a row to take it seven to zero. Prior to that point, both players were broken once, though Zverev had seven break points, compared to Kohlschreiber's four. They both landed over 60 percent of first serves (61% for Kohlschreiber and 64% for Zverev). 

Sets Two and Three

Kohlschreiber, who must make the third round to remain one of the top-32 male singles players in the world, responded well to his first set loss. He breezed through the next two sets, which he won 6-2 and 6-0, respectively. He also converted both of his break points in set two and all three in set three, while his opponent was unable to convert any of his three in the second set and did not have any break points in the third set. The second and third sets combined were shorter than the first set, lasting 33 and 25 minutes. 

Set Four

Zverev recovered superbly after being dominated for two sets. The Hamburg native, who has been ranked as highly as 74th in the world and is currently 82nd, broke the twenty-ninth seed twice over the 39-minute fourth set. He also won 83 percent of first serve points, compared to only 59 percent for his more highly-ranked opponent. The 18-year old won the set six games to two, showcasing the talent that has him called the future star of German tennis. 

Set Five

In the end, it was the veteran who managed to pull out the win with a single service break and an amazing forehand return winner on match point. Kohlschreiber, who is eight inches shorter than his younger opponent, took the set six games to four, and the match 6-7, 6-2, 6-0, 2-6, 6-4. Zverev struggled with the heat in the third set, which didn't help him. Many players have been having cramming issues during this tournament, including Wimbledon quarterfinalist Vasek Pospisil, who fell to the ground in pain during his first-round match, and fellow teen Thanasi Kokkinakis, who was forced to retire.

The kids are not all right: After Kokkinakis, Alexander Zverev also cramping in the 5th set - Philipp Kohlschreiber. pic.twitter.com/SMJyCAEHw9

— Live Tennis (@livetennis) September 1, 2015

Kohlschreiber cranked the FH return of his life to outlast young Zverev 6-4 in the 5th. At net, he barely came up higher than his shoulder

— Stephanie Myles (@OpenCourt) September 1, 2015

Next Up

Lukas Rosol is up next for the winner, before a possible third-round match against number two seed Roger Federer. Rosol beat American Jared Donaldson with an odd straight set scoreline, 7-6, 6-0, 7-6. Kohlschreiber has a three to one head-to-head record against Rosol.