If Roger Federer has had a flaw—or at least a perceived flaw—as a player, it has been his stubbornness. He knows how he wants to play, and what works best for him; and in 1,148 matches over the last 20 years, his instincts had proven correct. But because of that record, it can take a lot to convince Federer to change a game plan mid-match, or rethink his approach to a certain opponent. The most recent example of his champion’s obstinacy came in the quarterfinals of last year’s US Open, when he kept pounding the ball into Juan Martin del Potro’s forehand, and kept watching Del Potro pound it back harder.

During the first set and a half of Federer’s semifinal against Borna Coric at Indian Wells on Saturday, a similar dynamic took hold. Federer was flat at the start of this eye-opening 11 A.M. match. He missed first serves, he was passed at the net, he was on his heels at the baseline, and, when he did what his instincts told him to do—take the match into his own hands—he struggled to find an opening. Coric’s serve was sharp and his ground strokes sharper. When Federer tried to break down his backhand, Coric coolly rolled the ball into the corners with depth and pace. While Federer struggled to create in the swirlingly unpredictable wind, Coric kept hitting right through it.

Match point from Federer vs. Coric:

The 21-year-old Croat, who came into 2018 with a new coach, a new mindset, and a training regimen, said before the match that he was “playing the best tennis of my life.” If anything, he topped himself through the first half of this one. At 5-5 in the first set, he broke Federer by charging in off a second serve at 30-30, and ripping a forehand pass at break point. After winning the first 7-5, Coric began the second by breaking Federer with a forehand winner, a backhand winner, and another forehand winner. When Coric came back from 0-40 to hold at 2-1, it looked as if he had the game and the confidence to close Federer out.

But Federer himself wasn’t so sure. From that point on, having gotten nowhere with his usual aggressive game, he did what doesn’t come naturally: He changed course. He played with more margin and safety, and he sent the ball down the middle of the court, where Coric doesn’t like it. Federer knew that no matter how poorly he was playing, he still had one weapon: his reputation. He would give Coric every chance he could to get tight.

“I needed to fight,” Federer said afterward. “Try to keep the ball in play, no do too much shotmaking. It was difficult in the wind, because Borna was incredibly steady, playing deep and hard shots, tough to do anything off of.”

Federer admitted that it wasn’t easy to make himself dial his game back.

“Those 10 minutes, when he was up a set and a break, it was tough for me to accept, and go on with it and just say, ‘OK, I’m happy to stay in the game.’ Happy to stay in the rally and maybe he’s going to get a bit nervous, and that’s exactly what happened.”

Coric’s nerves began to show at 3-1 in the second. Up 15-30 on Federer’s serve, with a chance at a second break, he drilled a routine backhand pass into the net. But it wasn’t until he was serving at 4-3 that his game finally broke down. Coric made two easy errors to go down 0-30, and sent another backhand long at break point. From there, some of Coric’s traditional flaws—his lack of consistency on his forehand, his trouble handling balls down the middle, and his inability to get free points on his serve—began to crop up again. Up 4-2 in the second, he lost it 6-4 in a matter of minutes.

Credit Coric for never going away or melting down in frustration. This is a player who was tagged as Baby Djokovic as a teenager, and he showed today that the Djokovic model—an ultra-solid mix of depth, defense, and a steady, corner-to-corner attack—can still work against Federer. Even after squandering that second-set lead, Coric went straight back to building another in the third. He broke Federer at 0-0, and again at 3-3. Up 4-3, 40-30, Coric still seemed to have the match in hand as he worked himself into position for a down-the-line backhand into the open court. He had been making that shot for much of the third set, but this time, with a 5-3 lead over Federer looming, he sent it wide.

Coric had come a long way at Indian Wells over the last 10 days, but that was one backhand winner too far. Two points later, he double faulted and was broken, and Federer was home free. He won the last 11 points of the match, and even in the final game, the 36-year-old was able to sprint all the way across the baseline to track down a Coric volley and flick it back crosscourt for a winner that brought the crowd to its feet. Two hours and 28 minutes after it began, Federer had a 5-7, 6-4, 6-4 win, had extended his 2018 record to 17-0, and had reached his eighth final in Indian Wells.

“I feel like a just woke up!” the stubble-sporting Federer said with a smile, when he was asked about the early starting time.

Still, Federer had been conscious for long enough to realize something important: That playing the way he wanted to play wasn’t working. For the 1,149th time, he was right.

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