Goffin took down Thiem–the only remaining player who has ever defeated Federer–6-4, 6-1 to set up a semifinal showdown against the second-ranked Swiss on Saturday. The Belgian took 12 of the last 14 games against Thiem to cruise in just one hour and 11 minutes.

After falling into a quick 3-0 hole, Goffin reeled off five games in a row–a stretch that included a 14-0 run of points. Thiem finally got back on the scoreboard with a hold for 4-5, but Goffin held to 30 in the 10th game to wrap up the opening frame of play.

It was all but over for Thiem when he dropped serve at 1-1 in the third. In fact, the erratic Austrian was broken in each of his final three service games, the last of which ended his stay in London. Thiem had previously come close to breaking Goffin at 4-1, but the world No. 8 survive that game after eight deuces and four break points.

“I didn’t panic after the first three games,” Goffin explained. “I knew in the past I have the return to break him. I knew I will have some opportunity to break him.I did it right after the first three games. After that, I started to feel much better with my return, and I played well [the rest of the] first set.”

His reward is a seventh career meeting with Federer, who is dominating the head-to-head series 6-0 and 14-2 in total sets.

“I’ve never found a key to beat Roger,” Goffin admitted. “Honestly, I don’t know what to do tomorrow.”

And although the underdog is more than worthy of respect, why not look ahead to Federer’s almost certain appearance in Sunday’s championship? After all, Federer is just betterer than everyone else in London this week. Assuming he takes care of Goffin, the following numbers will come into play: Federer is also 6-0 against Grigor Dimitrov and 4-0 against Jack Sock. He is 36-5 in total sets against the other three semifinalists.

Thiem, meanwhile, is a surprising 2-1 in the head-to-head against Federer. But Thiem is gone. And in all likelihood, Goffin will be gone tomorrow.