Marcos Giron has taken down the favorite…

The 28-year-old Latino tennis player upset No. 1 seed Taylor Fritz — his practice partner — 6-4, 3-6, 7-6(3) on Friday to advance to the semifinals of the ATP Dallas Open.

Giron, the tournament’s seventh seed, battled back after losing the second set and falling behind 4-2 in the third set.

“When I was down a break in the third, we got a change of balls, and I was able to kind of take advantage of that,” Giron said. “Once I was able to sneak out a break, my level improved.”

By defeating the 19th-ranked player in the world, No. 70 Giron scored his fifth career win in 18 chances against top 20 players to reach his second ATP semifinal.

Fritz was playing in his first tournament as the top seed.

“I’ve practiced with Fritz so much,” Giron said. “We’re both based in L.A. and we both train in Carson so we know each other’s game well.”

Giron had the only service break in the first set against Fritz. Giron almost gave back a 5-4 lead by falling behind 30-40 but rallied to hold serve and win the set.

Fritz’s serving dominated the second set, winning three games without a point for Giron.

The third set looked similar as Fritz took a 4-2 lead. Giron broke Fritz to tie the match. Each player had a break and then held serve to send the match into the tiebreak. Then they both reached match point, but neither could win the point.

Giron never trailed in the tiebreak, and he scored the final three points to win when Fritz hit long. Fritz had won the only previous ATP match between the two.

In Saturday’s semifinals, Giron will meet No. 4 Jenson Brooksby, who dispatched Australian Jordan Thompson 6-3, 6-0.