Canadian Daniel Nestor and Belarusian partner Max Mirnyi closed out their round-robin schedule with a third straight victory at the ATP World Tour Finals on Thursday.
The third-seeded duo needed a match tiebreak to complete a 4-6, 6-3, 10-7 victory over Serbia's Nenad Zimonjic — Nestor's former partner — and Michael Llodra of France.
Nestor and Mirnyi were already guaranteed a berth in Saturday's semifinals before the match. They fell behind early before fighting back to lock up first place in Group B at 3-0.
"It's great to go into the semis with a winning record," said Nestor. "Everyone's really dangerous, the other three teams in our group have a lot of power, they are imposing teams. Anyone can win any event."
Nestor and Mirnyi improved to 4-2 lifetime against Zimonjic and Llodra. They also beat them in the French Open semifinals and in title matches at Shanghai and Basel.
"We hung tough and we have to keep doing it," Nestor said. "We're ready for the semifinals."
The eighth-seeded Polish duo of Mariusz Fyrstenberg and Marcin Matkowski also qualified out of Group B. Round-robin play in Group A wraps up Friday.
Nestor and Mirnyi needed 80 minutes to complete the victory.
In the match tiebreak, Nestor and Mirnyi fought back after dropping four of the first five points. They won the first of two match points as Mirnyi hit a spectacular down-the-line return winner to end it.
The 39-year-old Nestor teamed with Zimonjic to win the year-end tournament in 2008 and 2010. The Toronto player also won in 2007 with Mark Knowles of the Bahamas.
Nestor is hoping to earn his 75th career doubles title.