American qualifier Rajeev Ram had 17 aces to beat Pablo Andujar of Spain 6-3, 6-7 (5), 6-3 at the St. Petersburg Open on Tuesday.
The 166th-ranked Ram advanced to the second round for the first time since losing to Andy Roddick in Atlanta in July.
In other matches, third-seeded Janko Tipsarevic of Serbia and eighth-seeded Victor Hanescu of Romania advanced to the second round.
The 46th-ranked Tipsarevic beat two-time semifinalist Igor Kunitsyn of Russia 6-4, 6-2. Hanescu ousted 2009 runner-up Horacio Zeballos of Argentina 6-2, 6-0 in 54 minutes.
Tipsarevic, who lost to eventual champion Andy Murray in the quarterfinals in 2008, broke the 106th-ranked Russian three times. He served seven aces, hit 10 winners and lost only five points in his nine service games to win.
''A break in the opening game gave me confidence,'' Tipsarevic said. ''Serve is my key weapon and I really served well today.''
Tipsarevic will face American Michael Russell in the second round on Wednesday.
The 52nd-ranked Hanescu, the 2008 semifinalist, won eight consecutive games and never faced a break point.
Hanescu will next play Ram.
Also, sixth-seeded Denis Istomin of Uzbekistan retired with a right knee injury while trailing Illya Marchenko of Ukraine 6-2, 2-2.
''I had no time to recover after playing in the Kremlin Cup,'' said Istomin, who beat Marchenko in the first round on the way to the semifinals in Moscow last week. ''I felt constant pain in my knee and decided not to aggravate it as I still have two tournaments ahead to collect points.''
And Paul-Henri Mathieu of France advanced with a 6-4, 6-3 victory over Maximo Gonzalez of Argentina, while qualifier Evgeny Donskoy scored his first victory in an ATP event, beating fellow Russian wild card Andrey Kuznetsov 7-5, 7-6 (2).
