Saint Petersburg - Russia top seed Mikhail Youzhny battled from a set down to beat Romania's eighth seed Victor Hanescu in their Saint Petersburg Open quarter-final clash on Friday.
Youzhny, 2004 champion here, won 6-7 (5/7), 6-3, 7-6 (8/6) in two hours 46 minutes to record his fourth win over Hanescu in their seventh meeting.
Hanescu and Youzhny went toe to toe in the opener and in the ensuing tiebreak it was the 29-year-old Romanian veteran who was slightly more accurate to clinch the lead in 50 minutes.
In the second Youzhny broke early for a comfortable 3-0 lead, which he kept through top level at 1-1 after one hour 35 minutes on court.
In the deciding set the opponents again needed the tiebreaker to separate them which Youzhny won to make his sixth semi-final of the year.
Youzhny will now face compatriot Dmitry Tursunov, who ousted Ukraine's Alexandr Dolgopolov in straight sets 6-4, 6-2.
Meanwhile, Mikhail Kukushkin of Kazakhstan upset Serbia's third seed Janko Tipsarevic, winning their first meeting 7-5, 3-6, 6-4 in two hours 38 minutes to clinch a place in the last four.
Kukushkin, 22, broke in the 12th game to take the opening set in 56 minutes.
But Tipsarevic, currently 46th in the world, added power and precision in the second set to break twice to level the contest.
In the third set the 26-year-old Tipsarevic seized the lead with a break in the sixth game but Kukushkin moved up a gear and took four consecutive games to win the set and match on his first match point.
"It was a very tough match but the luck was on my side today," Kukushkin said. "I was trailing in the deciding set but managed to find the way to come back win the match. I'm happy to make my semi-final here."
In the semi-final Kukushkin will take on Ukraine's Ilya Marchenko, who saw off Benjamin Becker of Germany 6-4, 2-6, 6-2 in one hour 52 minutes.
Results:
Dmitry Tursunov (RUS) bt Alexandr Dolgopolov (UKR) 6-4, 6-2
Mikhail Youzhny (RUS x1) bt Victor Hanescu (ROM x8) 6-7 (5/7), 6-3, 7-6 (8/6)
Mikhail Kukushkin (KAZ) bt Janko Tipsarevic (SRB x3) 7-5, 3-6, 6-4
Ilya Marchenko (UKR) bt Benjamin Becker (GER) 6-4, 2-6, 6-2