Andy Murray is another major casualty in the men's draw at the US Open, with the third seed crashing out 6-7 (5), 3-6, 7-6 (2), 6-7 (0) at the hands of Kevin Anderson.
Murray joins fourth seed Kei Nishikori, and eighth seed Rafael Nadal in exiting the tournament before the quarter-finals.
Heading into the fourth round match, the 15th-seeded Anderson had a 0-15 record against top 10 players at grand slams and had never made it to the quarter-final of a slam, having lost in the fourth round on seven occasions.
But the South African brought his 'A' game to Louis Armstrong Stadium on Monday, and a highly frustrated Murray was unable to stop him.
Neither player faced a break point in the opening set, but it was Anderson who made the pivotal move in the resulting tiebreaker with a forehand winner handing him the breaker 7-5.
Anderson upped his game in the second set and grabbed an early break to go 2-0 up before securing a second break to take control of the set. Murray would break back to reduce the deficit to 5-3, and had a chance to bring the set back on serve, but Anderson stood firm to take the set 6-3.
Murray's frustrations began to boil over, with the Scot unleashing an expletive-ladened rant during the changeover as he voiced his displeasure at what he believed was an extended bathroom break from Anderson.
The world number three would have looked to channel those emotions somewhat better in the third set, but he started poorly with Anderson once again securing an early break. Murray broke back immediately before getting another game off Anderson to move ahead. However, Anderson was not done just yet and broke back to force a tiebreak.
Facing the prospect of a straight-sets defeat, Murray took control of the tiebreaker early and would triumph 7-2 to get on the board and send the match into a fourth set.
The quality of tennis in the fourth set was of the highest level, with neither man giving an inch – or providing their opponent with a look-in on their serve.
But, as had been the case for much of the match, it was Anderson who took charge at the key moment, and the 6-foot-8 South African claimed the first mini-break, and then another, and another. Before Murray knew what had happened Anderson had wrapped up the breaker to love and had taken the contest in four hours and 18 minutes.
Anderson fired down 28 aces and produced 41 winners in a performance which he called the best of his career, but perhaps the key statistic was break point conversion, with Anderson converting four of nine opportunities, while Murray was able to make the most of just three from 11.
While for Anderson the quarter-finals mean that new ground has been broken, Murray heads home before the last eight for the first time in the last 18 grand slams.
Next up for Anderson is a clash with Stan Wawrinka who defeated Donald Young 6-4, 1-6, 6-3, 6-4 earlier on Monday. Anderson holds a 3-2 head-to-head edge over Wawrinka.