Marat Safin opened his final Kremlin Cup campaign by ousting defending champion Nikolay Davydenko in the first round in Moscow.
Safin was runner-up in last year's final, and he came from a set down to win 4-6 6-4 6-2 and end Davydenko's bid for a fourth title in the Russian capital.
Safin, 29, who retires at the end of the season, produced 10 aces and a better all-round game against his 28-year-old opponent to win in a little under two hours.
Also through into the second round were Evgeny Korolev who beat fellow Russian Igor Kunitsyn 7-6 (8-6) 6-3 while qualifier Illya Marchenko was 4-1 up in the deciding set when Uzbekistan's Denis Istomin retired with a throat infection to seal a 1-6 6-4 4-1 result.
Russian third seed Mikhail Youzhny thrashed Potito Starace of Italy 6-1 6-1 in less than an hour, producing a superb service performance to reach the third round.
Pablo Cuevas, the fifth seed, had a tougher match but prevailed 3-6 6-1 6-4 against Teimuraz Gabashvili.
However, seventh seed Fabrice Santoro crashed out in straight sets to qualifier Sergiy Stakhovsky of Ukraine.
Stakhovsky hit 11 aces and produced a far more incisive game to win 7-5 6-1 to overcome a deficit of 60 ranking places.
Meanwhile, top seed Robin Soderling enjoyed a smooth passage into the second round of the Stockholm Open.
Swede Soderling, a French Open finalist earlier this season, delighted the home crowd with a 6-3 6-0 win over Ecuador's Giovanni Lapentti.
Germany's Tommy Haas was also a comfortable winner, taking 55 minutes to ease past France's Florent Serra with a 6-3 6-4 victory, firing down 17 aces in the process.
In-form Marcos Baghdatis continued his comeback from injury with a 6-4 6-2 win over third seed Juan Carlos Ferrero.
Baghdatis, who has won three Challenger titles recently - including in Tashkent last week - created four breaks of serve and fired down 13 aces against the former French Open champion.
Feliciano Lopez beat Ernests Gulbis in straight sets while, in second-round action, there were also wins for Lopez's fellow Spaniard Guillermo Garcia-Lopez, who saw off Germany's Simon Greul, and Brazil's Thomaz Bellucci.
Bellucci beat Argentina's Leonardo Mayer 7-5 3-6 6-3.