The 6th in the world overcame in three sets 6-4, 3-6, 7-6 (7/2) and 2 h 31 min of play from his opponent, 20th in the ATP ranking.
Tsitsipas signed his 40th victory of the season, more than any other player on the circuit, and now has nine titles to his name, including two this year after the Masters 1000 in Monte-Carlo.
After an easily won first set, the 23-year-old Greek couldn't do anything in the second set against Bautista who equalized at one set all.
In the decisive set, the Spaniard first took the advantage by breaking Tsitsipas to lead 5-3, but the Greek immediately returned to his height and dominated the tie-break to sign his third victory in as many duels with Bautista.
"It seems that my matches on grass last longer than those I play on clay," he remarked after his victory.
"It was an incredible match, a fantastic battle (...) For tennis, it's great to offer matches of such a level", he insisted.
After his failure in the round of 16 at Roland Garros where he had been eliminated by the Dane Holger Rune, Tsitsipas reassured himself before approaching Wimbledon where his best result is an 8th final (2018) and where he had been eliminated as soon as his debut last year.
He is probably safe from such a mishap this year: his first opponent will be the Swiss Alexander Ritschard, from qualifying and 192nd in the world.
But the horizon of the Greek, who will be 4th in the ATP ranking on Monday, could quickly darken: in the quarter-finals, he could meet the Italian Matteo Berrettini (11th), impressive this season on grass with titles in Stuttgart and Queen's.
© 2022 AFP