Italian Matteo Berrettini fell 6-7(8) 6-4 6-3 to Alexander Zverev as Zverev claimed his second Madrid Open title.
Germany's Zverev, conqueror of claycourt specialists Rafa Nadal and Dominic Thiem en route to the final, dropped his first set of the tournament. However, he fought back under a closed roof at the Manolo Santana stadium to lift his first claycourt title since 2019.
"I feel awesome," Zverev said at a courtside interview. "It's great. This is definitely a special win. I just want to enjoy it. I didn't play too many guys who can serve like him, so it was a difficult match."
Murray: Djokovic has unique claim to be GOAT
Berrettini showed no sign of nerves in his maiden ATP 1000 final and landed the first blow, taking a see-sawing opening set in a tie-break, where he initially let slip a 5-0 advantage and then saved a set point.
But Zverev, who was champion in Madrid in 2018, hit back strongly in the second set, breaking the 25-year-old Italian in the ninth game to force a decider.
- Sabalenka v Barty is the match-up 2021 - But who's the French Open favourite?
- Osaka says risk of staging Olympics must be carefully weighed
- Sabalenka downs world number one Barty to claim Madrid crown
With unforced errors creeping into Berrettini's game, the Italian squandered a break point at 2-2 and then proceeded to drop his own serve as Zverev inched closer to victory.
The fifth seeded German did not let up and another break confirmed the win in two hours and 40 minutes.
Zverev will shift his focus to Rome next week before continuing his pursuit of a maiden Grand Slam title at Roland Garros, where he has never been beyond the quarter-finals.
"It's difficult to switch, but Rome is also an event I like and I hope I can perform the same way," Zverev said.
Nadal defeated by Zverev in Madrid Open quarters
Wilander: Osaka will be back stronger than ever after Wimbledon withdrawal
Opinion: Wimbledon and Olympic withdrawals inevitable, and more will follow