Some looked at Gilles Muller as just another opponent in Rafael Nadal’s path to the quarterfinals at Wimbledon. But the veteran turned out to be much more than that as he derailed the recent Roland Garros champion and became the first player to make inroads into the Big Four’s success at SW19.

In a high-quality, compelling match of tennis, Muller defeated Nadal 6–3, 6–4, 3–6, 4–6, 15–13 to advance to the gentleman’s singles quarterfinals.

At 34-years of age, the native of Luxembourg has found his career-best tennis this year. And on Monday, he played poised, smart, and solid tennis throughout the nearly 5 hours on Court One.

Muller signaled that he would not be intimidated by the hottest player on tour in recent months as he controlled play early behind a strong serve and big, deep groundstrokes. Nadal showed a weakness in the opening sets as he was unable to gauge Muller’s serve for much of the first couple sets. The Spaniard often guessed incorrectly or was unable to make good contact on the big lefty’s first strike. And as he moved well behind the baseline to better control his return of serve, Muller took advantage, coming forward to control the points.

However, Nadal has not won 15 grand slam tournaments by laying down when facing adversity and he did not in this match. After dropping the first two sets and tweaking his ankle, he continued to fight and finally began to read Muller’s serve. And as a sense of urgency entered his play, he turned the match around.

Nadal controlled the third and fourth sets by grounding out his signature forehand and dominating his first-serve points. In these two sets, the Spaniard struck 28 winners to just 5 unforced errors. He entered the fifth and deciding set with all the momentum.

But the fifth set was one of missed opportunities by the four-seed. As the match went well beyond one that would have been decided by a tiebreak at other tournaments, the two players fought to hold serve. For most of the set, it was Muller finding it easier to hold serve while Nadal was forced to battle to maintain his. Nonetheless, Nadal held strong, overcoming 4 match points in the process. However, the times when he had an open door against the Muller serve, it quickly shut as he could not capitalize. Nadal had five break opportunities in the set but could not convert any. And in the 28th game, Muller finally broke through to take the set and win the epic match.

Clearly disappointed as he faced the press afterward, Nadal was not in the mood for silver linings. Asked if he considered the tournament to a success for him after recent difficulties at Wimbledon, Nadal replied, “I lost in the fourth round. That’s not the result I was expecting. It’s true that I played some good matches, but the same time is true that I didn’t want to lose that match. So is tough to analyze in a positive way right now. He continued, “Yeah, I won matches. I play better than other years, true. At the same time, I was ready for important things, so I lost an opportunity.”

Despite winning more points in the match (198-191) and playing more efficient as he struck 77 winners to just 17 unforced errors while Muller struck 95 winners and 52 unforced errors, there was one glaring statistic. Nadal had 16 break opportunities and only took advantage of 2 of those.

Nadal pointed to his slow start as a key to the match afterward, “I had my chance in the beginning,” he said. “Is stupid to say now, but maybe if I had that break at the first set, third or fourth game, maybe we are in a completely different situation. But I didn’t.”

Meanwhile, Muller had a difficult time putting the result into words, “I haven’t really realized what just happened,” he said. “It’s a great feeling. I was thinking about if I had to come back next day to finish the match (because of darkness). I am just pleased to get it finished and be in the quarter-finals. I was two sets up, played really well and then Rafa stepped it up. At the end, it was just a big battle.’’

Muller survived the battle and will face Marin Cilic next. The Croat continued his great play in London with a 6-2, 6-2, 6-2 win against Roberto Bautista Agut. “My confidence is quite high, considering I've been playing really well over the past few weeks,” said Cilic

Meanwhile, it was Sam Querrey who, once again, became the last American man standing at Wimbledon after a 5-7, 7-6, 6-3, 6-7, 6-3 win over Kevin Anderson. Milos Raonic has elevated his game again and survived a tough 4-6, 7-5, 4-6, 7-5, 6-1 against Alexander Zverev on Court 2. Elsewhere, veteran Tomas Berdych outlasted 8th-seed Dominic Thiem 6-3, 6-7, 6-3, 3-6, 6-3 and top-seeded Andy Murray swept past Benoit Paire 7-6, 6-4, 6-4

One match was moved to Tuesday due to darkness. 2nd-seeded Novak Djokovic will be first up on Centre Court tomorrow as he faces Adrian Mannarino at high noon. The men’s quarterfinals will take place on Wednesday.