Second-seeded Tomas Berdych saved three match points before rallying to beat Ruben Bemelmans 5-7, 7-6 (8), 6-4 on Tuesday to reach the second round of the Gerry Weber Open.
The Czech faced the match points in the second-set tiebreaker before finishing off the Belgian in 2 hours, 16 minutes at Wimbledon warm-up.
"I believed until the very last point was played. I was feeling quite good on the court even though the score didn't look like that," said Berdych, who won the tournament in 2007. "I know how tough it is to close the match, and I used my experience over him."
Berdych only broke Bemelmans' serve once, to open the third set, and sealed the match with an ace.
Berdych is the highest seeded player remaining after No. 1 Roger Federer withdrew on Monday. But the 2010 Wimbledon finalist does not want to be called the favorite.
"That's just how the people and the media look at the tournament," he said. "For me it's the same regardless of my seed. If I do well I have a chance to win the tournament."
Third-seeded Gael Monfils of France eased past compatriot Florent Serra 6-4, 6-3 in just 56 minutes in his Gerry Weber debut.
Monfils, ranked a career-high eighth this week, will next face Ivan Dodig of Croatia.
However, 2009 winner Tommy Haas of Germany was eliminated after losing to Andreas Seppi of Italy, 6-2, 6-7(6), 6-3. Haas, who was playing in his second tournament after undergoing right hip and right elbow surgery last year.
"I played well at times. I was forcing it, wanting it too much," Haas said. "I just need to play matches. You can't practice getting to the second round of a tournament."
Earlier, fifth-seeded Viktor Troicki and eighth-seeded Milos Raonic both breezed into the second round with easy victories.
Troicki, who helped Serbia win the 2010 Davis Cup title, needed just 53 minutes to get past Mischa Zverev of Germany 6-2, 6-3. Troicki will next play Igor Andreev of Russia in the second round of the Wimbledon warmup tournament.
Raonic took just a bit longer to dispatch of Pablo Andujar of Spain 6-3, 6-1. The 20-year-old Canadian's second-round opponent will be Tobias Kamke of Germany.
The sixth-seeded Florian Mayer had a harder time beating German compatriot Dustin Brown 7-6 (6), 2-6, 6-3.
Mayer, who next plays Yen-hsun Lu of Taiwan, came into the tournament with his highest ever ranking at No. 18. He is also his country's No. 1, but said that was of no significance.
"Of course I have more self-confidence, but that's because I'm number 18 in the world not because I'm number one in Germany, Mayer said. "The most important thing for me is to move further up the world rankings.
"If someone else, Philipp Kohlschreiber or Philipp Petzschner, would be 15th and I were 16 or 17, my self-confidence would be the same as Germany's number 2."
Petzschner also reached the second round on Tuesday with a 6-2, 7-6 (5) win over another German, Dominik Meffert, and will next face Daniel Gimeno-Traver of Spain, who came back for a 1-6, 7-6 (5), 6-2 victory over Kazakhstan's Andrey Golubev.