Rublev was also aiming for back-to-back titles after winning the ABN AMRO World Tennis Tournament in Rotterdam on Sunday.
The Russian was in the unusual position of playing a semifinal without having spent a minute on court in the singles tournament following a bye and two walkovers, though he had been playing doubles. Rublev served eight aces but still had his serve broken four times by Bautista Agut.
Bautista Agut is into his second final of 2021 following a loss to David Goffin in Montpellier last month. His win at the Qatar Open in January 2019 remains his most recent title on the tour.
Basilashvili is in his first final since July 2019 after a Qatar campaign which included a win over Roger Federer‘s in the quarterfinals.