WHAT HAPPENED: The youth and enthusiasm of Borna Coric proved too much for the age and experience of Florian Mayer on Day 1, as the 21-year-old Croatian advanced to Round 2 with a comfortable 6-2, 6-2, 5-7, 6-4 victory.

The Croatian proved too strong and steady throughout, controlling the match with heavy baseline hitting that seldom wavered throughout two hours, 26 minutes on a 90-plus degree day. His only notable faux pas came at the start of the second set, when both he and Mayer sauntered to the wrong side of the court at the start of play.

Coric sprinkled plenty of variety in between his punishing ground strokes, never more so than in securing the decisive break in set two. With Mayer serving at 2-2, the Croatian opened with a wicked down-the-line slice that carved deep into the doubles alley on Mayer’s backhand wing. The artful shot induced an easy put away for Love-15, and he continued to make Court 7 his canvas with an inch-perfect drop shot to follow. A precise backhand pass earned Coric three break points, and he converted immediately with a deep, driven return that Mayer could not steer back.

Despite a pair of 6-2 sets to open the match, Coric was forced to save a combined five break points across both sets. The pressure finally paid off for Mayer in set three, when he cashed in twice to break his opponent. A down-the-line backhand return at 5-6 sealed the set, as the German fought to extend his 17-year professional career.

But an early break in set four put Coric back in command, and he served out the match without facing a break point to advance to the second round for the third time in his US Open career.             

WHAT IT MEANS: The loss sends Mayer, 34, into retirement as he exits the 12th US Open of his career. The German reached a career-high ranking of No. 18 in 2011, with his best performances coming in 2011 and 2013, when he reached the third round. He is a two-time Grand Slam quarterfinalist, having reached the last eight at Wimbledon in 2004 and 2012.

Mayer announced his plans to step away from the game to the Bavarian Tennis Association in April. “The young players in their early 20s are coming in, highly motivated, fit, playing very hard and athletic, making it harder and harder to stay in the Top 100 every year,” he explained.

No doubt Coric is one of those up-and-comers he was referring to. One year after he produced one of the upsets of the 2017 US Open by defeating then-No. 4 seed Alexander Zverev in the second round, the Croatian has started strong once again in New York.

MATCH POINT: Coric has jumped 41 places in the ATP rankings since his last US Open appearance, from No. 61 to No. 20. Though his career is just starting to take off, 2018 is the fourth consecutive year in which he has featured in the main draw of all four Grand Slams.