After losing the first set, 6-1, and going down a break, 3-1, things were not looking good for Andrey Rublev in Beijing. Undeterred, the 19-year-old battled back, with the help of his lethal forehand, to upset Tomas Berdych.

The No. 39-ranked Russian won 11 of the next 13 games to advance to his fourth ATP quarterfinal of the season. The 1-6, 6-4, 6-1 victory also marks the third Top-20 win of his career (after beating Grigor Dimitrov and David Goffin on his way to the US Open quarterfinals).

It's obvious that Rublev doesn't give up, ever—even when he's out of the draw. After losing in the qualifying of Umag earlier this season, the teenager got tossed into the main draw mix as a lucky loser. He took that second chance all the way to his first career ATP title. How about that for determination?

He next takes on fellow ATP youth Alexander Zverev for a spot in the semifinals. They have played just once before with Zverev winning handily in Monte Carlo last year.