Roger Federer booked his spot in the quarter-finals of the US Open courtesy of a 7-6 (0), 7-6 (6), 7-5 victory over John Isner.
The big-serving Isner was a potential banana skin for Federer, but the second seed looked in good form on his way to a straight-sets win in two hours and 40 minutes.
While Federer struggled to break Isner, who served 17 aces, he was in near complete control on his own serve, producing 15 aces of his own and winning 83 percent of points on his own serve.
The Swiss maestro lost just seven points on his serve in the first set, but was unable to capitalise on any of the three break point opportunities that he engineered on the Isner serve as the opener headed for a tiebreak.
With such a booming serve, Isner is no stranger to tiebreakers, he has contested 427 at tour level, but the 13th seed was made to look pedestrian as Federer upped his game to hand Isner his first tiebreaker bagel.
The second set was much like the first, with Isner unable to match Federer's groundstrokes, but able to use his first serve to keep himself in the contest.
Once more a tiebreaker was required, and Isner would not be caught cold on this occasion and fought his way to a 4-2 advantage. However, Federer wrestled the initiative and closed out the set on his second attempt.
With the finish line in sight, Federer began to slowly make inroads on the Isner serve, but to the American's immense credit he refused to fold.
With Isner seerving at 0-40 down in the eighth game of the set, one would have expected Federer to secure the break, but Isner rallied to hold serve, as he would go on to do from 0-30 down in the tenth game. However, Federer would not be denied and after Isner once again went 0-40 down when serving to stay in the match at 5-6, he was able to save one match point, but not all three as Federer progressed to the last eight.
The world number two will face Richard Gasquet in the quarter-finals after the Frenchman beat Tomas Berdych 2-6, 6-3, 6-4, 6-1.
Earlier in the day, third seed Andy Murray was sent crashing out 6-7 (5), 3-6, 7-6 (2), 6-7 (0) by Kevin Anderson, while Stan Wawrinka beat Donald Young 6-4, 1-6, 6-3, 6-4.