Richard Gasquet will face Kei Nishikori in the semifinals of the Japan Open after the Frenchman defeated No. 2 seed Kevin Anderson 7-6(6), 7-6(4) on Thursday.
Gasquet won a crucial game late in the second set, breaking Anderson as he was serving to level the match to force a second tiebreak.
The world No. 25 then raced to a 6-2 lead in the tiebreak before converting his third match point to seal his first semifinal since the Swedish Open in July.
No. 3 seed Nishikori dispatched No. 5 seed Stefanos Tsitsipas in one hour, 24 minutes to advance to his fourth Japan Open semifinal, and his first since 2015.
With the opening set level at 3-3, the world No. 12 won six games in a row to clinch the first set and take a commanding 3-0 lead into the second.
Gasquet has won seven of his nine previous matches against Nishikori, most recently at the 2016 French Open.
In the other quarterfinals, Denis Shapovalov saved a match point as he defeated Jan-Leonard Struff 4-6, 7-6(7), 6-4.
19-year-old Shapovalov will face Daniil Medvedev in the semifinals, after he knocked out three-time finalist and No. 6 seed Milos Raonic 7-6(4), 6-3.