PARIS — At the mere mention of Novak Djokovic’s name, at the mere thought of sharing a court with a 17-time Grand Slam champion and the French Open’s No. 1-seeded man, Daniel Elahi Galan broke into a wide smile Thursday.

He used these phrases: “really, really excited” and “really, really happy” and “really, really special.”

Galan is, after all, ranked 153rd and never had won so much as one main-draw match at any major tournament until this week. Making this run to the third round even more improbable: The 24-year-old from Colombia lost in qualifying at Roland Garros and got into the bracket only when other men withdrew from the field.

So, sure, it was a big deal for Galan to beat Tennys Sandgren 6-2, 6-2, 6-3 on Thursday. And, to be sure, a bigger deal to contemplate Saturday, when he will face Djokovic, who has dropped a total of 10 games through two matches so far after overwhelming Ricardas Berankis 6-1, 6-2, 6-2 — and is someone Galan has spotted in the locker room but never spoken to.

“Just try to win,” Galan said of his mindset heading into the David vs. Goliath matchup. “Just give it all you have. And that’s it. At the end of the day, it’s just another match.”

So the obvious question: How do you, as the owner of two career Grand Slam match victories, maintain sufficient self-belief and hope ahead of facing Djokovic, whose 292 wins at majors include 70 at the French Open alone?

“Well,” came Galan’s reply, “I was wondering that, to be honest.”

Roberto Carballes Baena authored an upset of his own on Thursday.

He advanced by beating ninth-seeded Denis Shapovalov 7-5, 6-7 (5), 6-3, 3-6, 8-6 in a match lasting five hours.

Shapovalov committed 106 unforced errors in the match, compared to 42 for Carballes Baena, and twice served for the match. The Canadian also had more winners than Carballes Baena, 65-31.

Carballes Baena sank to his knees after Shapovalov hit a forehand long and let out a loud shout of delight.

“It is a dream for me to win a match like this on this court. I tried to be very solid and focus on my game,” the Spaniard said. “He’s very aggressive but I think I did a very good match.”

Shapovalov complained about everything from the French Open’s “trash scheduling” and its “freezing” weather, to a call on a shot by his opponent that looked “one inch out” to the “annoying” state of the clay and tennis balls after the match. He seemed most annoyed about having to play a doubles match later that night.

“Scheduling is absolutely awful. I mean, after a five-hour match I have to play doubles now,” he said a couple hours before losing that doubles match in straight sets.” It’s just like, it’s just complete trash scheduling. It’s disappointing.

“I mean you’re in a Grand Slam — and I don’t want to sound spoiled, you know, but you expect at least some help from the tournament to help you compete. I mean, how am I supposed to come out and play doubles now after a five-hour match?”

Carballes Baena will next play 18th-seeded Grigor Dimitrov, who has never reached the fourth round at Roland Garros.

Other upsets in men’s play included Kevin Anderson of South Africa beating No. 22 Dusan Lajovic in five sets and Daniel Altmaier besting No. 30 Jan-Lennard Struff in three. Anderson will play No. 13 Andrey Rublev next, while Altmaier will face off against No. 7 Matteo Berrettini.

No. 5 Stefanos Tsitsipas also breezed past Pablo Cuevas in straight sets. He’ll face Aljaz Bedene on Saturday.

The Associated Press contributed to this report.