WHAT HAPPENED: Nick Kyrgios saved the best for last against Mikhail Youzhny, overcoming a near meltdown and the No. 21 seed, 7-5, 7-6, 2-6, 7-6.
After Kyrgios and Youzhny played a long opening game, youth and experience each dug their trenches behind the serve, and most games ended without intrigue. Kyrgios, 19, would have the trainer take a brief look at his left arm, but the Australian hardly looked hindered as the match progressed. Kyrgios would cruise on serve in the opener, dropping only 10 points. A long 10th game proved decisive for the young Australian, who would break the 32-year-old Russian and run away with the opening set, 7-5.
Down an early break in the second set, the Russian emerged from a medical timeout playing fearless tennis. Kyrgios would lose serve for the first time and earn the first of three code violations for ball abuse. Youzhny consolidated the break and inched ahead of an increasingly frustrated Kyrgios. Serving for a tiebreak, Kyrgios put down his 11th ace of the match to level the set. The serve would carry the Australian sensation through a tense tiebreak.
The third set opened with a second break for Youzhny and a point penalty for Kyrgios, who uttered an audible obscenity. The Russian saw his lead widen late when he broke Kyrgios for the third time in the match and survived another marathon service game to clinch the third set, 6-2.
Looking to make up for a lackluster set, the Australian fell behind to open the fourth with a wild overhead miss on break point. Youzhny kept up his momentum with more stunning backhands. Looking to break back, Kyrgios uttered a second audible obscenity to earn a game penalty. An infraction from being defaulted, the 19-year-old played some of his best tennis in the 10th game to break the Russian with a searing backhand down the line. Another backhand winner to open the 12th game set the tone for a dominating tiebreak.
WHAT IT MEANS: Kyrgios next plays Italy’s Andreas Seppi, who had a much easier opener with a straight-sets win over Ukrainian veteran Sergei Stakhovsky. Kyrgios could potentially play No. 16 seed Tommy Robredo in the third round.
Youzhny is no stranger to success at the US Open. The No. 21 seed reached the semifinals twice in his career (2006, 2010) and came into the 2014 US Open having made the quarterfinals the year before. The Russian veteran has not failed to go past the second round at a major tournament this season.
Kyrgios came into the US Open with plenty of buzz. The teenager made a splash at this year's Wimbledon championships, where he toppled two-time US Open champion Rafael Nadal in four sets en route to the quarterfinals. Kyrgios is close to his career-high ranking but suffered through an injury-interrupted summer, in which he only played two matches during the Emirates Airline US Open Series.
THE QUESTION: How soon can Kyrgios herald the arrival of the next generation of players?