Naomi Osaka exited the Qatar Open with a narrow quarterfinal loss to fellow former world No. 1 Karolina Pliskova on Thursday.
Pliskova crept into the semis with a 7-6(6) 7-6(5) victory over the four-time major winner from Japan after both sets went to tiebreaks.
Osaka, who returned from a maternity break at the Brisbane Open in January, was playing in the last eight at a tournament for the first time in nearly two years.
Looking to avenge the first loss of her comeback to Pliskova in Brisbane, Osaka made a strong start by going up 5-3 in the first set in Doha.
The Czech player got back on level terms at 5-5 and went up 6-5 before Osaka saved a set point and forced a tiebreak.
Osaka sent the second set to a tiebreak after saving one match point at 5-4 and two more at 6-5. Pliskova sealed it on her fourth match point after reaching 6-5 in the tiebreak, with Osaka miscuing her service return.
"We played already (this year) so I knew it was not going to be easy," said Pliskova, who will face Polish world No. 1 Iga Swiatek in the semis.
Osaka won back-to-back victories in Qatar over Caroline Garcia and Petra Martic before reaching the quarterfinals via a walkover against injured round-of-16 opponent Lesia Tsurenko.
