Davydenko was inserted into the draw's No. 1 position when top-seeded Tomas Berdych withdrew with a wrist injury. That gave Davydenko a first-round bye but also put him against Jarkko Nieminen, who posted a 6-3, 7-6 (10-8) second-round upset.
Nieminen took the first set with a pair of breaks and had another in the second set that led to the extended tiebreaker.
Paire rallied for a 4-6, 7-6 (13-11), 6-4 win over Steve Darcis in his second-round match. Paire won just two more points (117-115) than Darcis on the day. He dropped serve twice in the first set but saved the other two break points he faced the rest of the way.
No. 6-seeded Julien Benneteau advanced 6-3, 4-2 when Adrian Ungur retired and seventh-seeded Viktor Troicki topped Lucas Pouille 6-4, 7-5 in first-round match.
Also in the first round, Tatsuma Ito eliminated Edouard Roger-Vasselin 3-6, 7-6 (7-5), 7-5; Arnau Brugues-Davi topped Mikhail Kukushkin 7-6 (7-5), 3-6, 7-5 (7-3); and Michael Llodra was on the court 60 minutes in a 6-3, 6-3 win over Kenny De Schepper.