Paris - Argentinian Diego Schwartzman said the story of David and Goliath helped him stage a thrilling comeback from two sets down to beat Kevin Anderson, who is 13 inches taller than him, and reach the French Open quarter-finals on Monday.
The 11th seed was totally outplayed in the first two sets, but twice broke Anderson when the South African was serving for the match en route to a 1-6, 2-6, 7-5, 7-6 (7/0), 6-2 victory.
Schwartzman, who stands at 5-foot-7 (1.7m), said the famous biblical story of David killing giant Goliath with a pebble helped him believe he could down the 6-foot-8 (2.03m) Anderson.
"Did you read David and Goliath? That's why. That's why," he explained.
"I read it when I was young in school, and I just try to think that when I see Kevin or the guys who have two metres."
The crowd on Court Suzanne Lenglen got behind the world number 12 as he dug deep to stay in the match, breaking Anderson when the sixth seed was leading 5-4 in both the third and fourth sets.
"When you're not as strong or you're not as tall as Anderson, you can still win the match," Schwartzman said.
"I think that people like me more, as well, for that, because they were supporting me. They wanted me to remain in the game.
"The fact that he was twice as tall as me was a reason for me to try and remain. But on serve, you can have a very good serve whether you're tall or small. That didn't have anything to do with it."
The 25-year-old, who also reached the quarter-finals at last year's US Open, will next face the giant of Roland Garros - 10-time champion Rafael Nadal - for a semi-final place.
Schwartzman has lost five times from as many meetings with Nadal, but took a set off him in the Australian Open last 16 earlier this year before pushing him hard in a loss on clay in Madrid.
"All the matches I played against him I had my chances," he added.
"So I need to recover well again, because to have those chances I need to be my 100 percent against him, and more here because he's always playing great tennis here.
"So, yeah, I know I am going to have chances, but then I need to take (them)."
World number seven Anderson, who was looking to become the first South African man to make the last eight since Cliff Drysdale 51 years ago, has now lost in the fourth round at Roland Garros on four occasions.
Results from day nine of the French Open at Roland Garros on Monday (x denotes seeding):
Rafael Nadal (ESP x1) bt Maximilian Marterer (GER) 6-3, 6-2, 7-6 (7/4)
Diego Schwartzman (ARG x11) bt Kevin Anderson (RSA x6) 1-6, 2-6, 7-5, 7-6 (7/0), 6-2
Marin Cilic (CRO x3) bt Fabio Fognini (ITA x18) 6-4, 6-1, 3-6, 6-7 (4/7), 6-3
Juan Martín Del Potro (ARG x5) bt John Isner (USA x9) 6-4, 6-4, 6-4
Simona Halep (ROM x1) bt Elise Mertens (BEL x16) 6-2, 6-1
Angelique Kerber (GER x12) bt Caroline Garcia (FRA x7) 6-2, 6-3
Garbiñe Muguruza (ESP x3) bt Lesia Tsurenko (UKR) 2-0 - retired
Maria Sharapova (RUS x28) bt Serena Williams (USA) - walkover
Daria Kasatkina (RUS x14) bt Caroline Wozniacki (DEN x2) 7-6 (7/5), 6-3