American Taylor Dent rallied to beat Frenchman Romain Jouan 6-7(5), 6-3, 6-4 in the first round of the Open Sud de France at Montpellier on Tuesday.
Dent hit 20 aces but also served nine double faults en route to victory.
In the other matches, Mischa Zverev needed two tie-breakers to beat Robin Haase 7-6(7), 7-6(5) while Steve Darcis defeated Eduardo Schwank 6-2, 7-5.
At the Vienna Open on Monday, former World No. 1 Thomas Muster, 43, returning to the ATP circuit after an 11-year absence, enjoyed a lucky break when first round opponent Ernests Gulbis pulled out.
The Latvian, seeded fifth and ranked 24th in the world, was replaced by Muster's fellow Austrian Andreas Haider-Maurer, a lucky loser ranked 157th.
Organisers said Gulbis withdrew for personal reasons.
Muster, French Open champion in 1995, was given a wildcard for the tournament.
Ranked 974th, Muster began his comeback earlier this year in the lower-level Challenger Tour and has managed one win in seven outings, against Borut Puc in Slovenia last month.
The ATP said the Austrian would become the first 40-plus to compete in the main draw of an ATP tournament since Jimmy Connors played in Atlanta in 1996, also at 43.
In other action on Monday, German seventh seed Philipp Kohlschreiber, a semifinalist in the last two editions, started with a convincing victory over Colombian Alejandro Falla 6-0, 6-3.
The field is led by top-seeded Austrian Jurgen Melzer who will be defending his title.
Chardy shocked
At St. Petersburg, Kazakhstan's Mikhail Kukushkin shocked Jeremy Chardy 6-7(3), 6-1, 6-0, his second victory over the Frenchman in successive tournaments.
The results:
At Vienna (Bank Austria Tennis Trophy): First round: Michael Berrer bt Guillermo Garcia-Lopez 6-3, 4-6, 7-5; Pablo Cuevas bt Thiemo de Bakker 7-6(6), 1-6, 6-4; Lucasz Kubot bt James Blake 6-4, 6-4; Santiago Giraldo bt Xavier Malisse 6-4, 1-6, 6-1; Philipp Kohlschreiber bt Alejandro Falla 6-0, 6-3; Andreas Seppi bt Martin Fischer 6-3, 6-3; Jan Hajek bt Pere Riba 6-0, 6-2.
At Montpellier (Open Sud de France): First round: Taylor Dent bt Romain Jouan 6-7(5), 6-3, 6-4; Mischa Zverev bt Robin Haase 7-6(7), 7-6(5); Steve Darcis bt Eduardo Schwank 6-2, 7-5; Albert Montanes bt Arnaud Clement 6-4, 6-4; Richard Gasquet bt Julian Reister 6-7(8), 6-3, 6-3; Frederico Gil bt Edouard Roger-Vasselin 6-4, 2-6, 7-5.
At St. Petersburg (St. Petersburg Open): First round: Michael Russell bt Igor Andreev 6-1, 7-5; Teimuraz Gabashvili bt Filippo Volandri 3-6, 6-3, 6-2; Mikhail Kukushkin bt Jeremy Chardy 6-7(3), 6-1, 6-0.
Doubles: Rohan Bopanna & Aisam-ul-Haq Qureshi bt Sergiy Stakhovsky & Mikhail Youzhny 6-2, 2-6, 10-3.