Roberto Bautista Agut will face Novak Djokovic in the semi-finals of the Mubadala World Tennis Championships after seeing off Andrey Rublev in straight sets.
Rublev, selected for the exhibition event in Abu Dhabi as a late call-up after Stan Wawrinka and Milos Raonic withdrew through injury, was beaten 7-5 6-2 on Thursday.
World number 20 Bautista Agut, a two-time winner on the ATP Tour in 2017, was broken when serving for the first set at 5-3 and then saw three set points come and go in the next game.
He recovered to break again in game 12, however, and looked largely untroubled in the second set, building on a 3-0 lead to book a meeting with Djokovic by converting his fourth match point when Rublev netted a forehand.
Kevin Anderson had better luck than his fellow replacement Rublev, defeating Pablo Carreno Busta 6-3 7-6 (7-2) and the US Open finalist will take on Dominic Thiem in the last four on Friday.
Rublev and Carreno Busta will contest a fifth-place play-off earlier that day.