Tomas Berdych needed a break in the final game to seal a surprisingly difficult 7-6 (7/3), 6-4 win over Romanian qualifier Marius Copil at the Rotterdam World Tennis on Monday.
The fourth-seeded Berdych, winner of the indoor title at the Ahoy stadium three years ago, was matched by the challenger at 11 aces each in a contest going just over 90 minutes.
Berdych saved all three break points he faced while breaking once to reach the second round.
"I won in 2014 but I'm not not superstitious, it would be a nice tradition to do it (win) again," Berdych said as he started his 10th appearance at the event in the Dutch port city.
"I like to come here, it's always a tough field with a lot of good players."
Frenchman Pierre-Hugues Herbert booked the first of the second-round spots, beating Spanish veteran Feliciano Lopez 7-6 (7/5), 7-6 (7/5).
Dutchman Robin Haase defeated German Florian Mayer 7-5, 7-6 (7/3) while Evgeny Donskoy of Russia dispatched Marcel Granollers 6-4, 6-4.
Rotterdam boss Richard Krajicek said the entries of weekend title-winners Alexander Zverev and Grigor Dimitrov would soften the box office blow after Rafael Nadal and Stan Wawrinka withdrew due to injury.
The tournament was left to feature former US Open winner Marin Cilic as top seed, with the 2014 Rotterdam finalist starting his current campaign against quirky Frenchman Benoit Paire on Tuesday.
The seventh-ranked Cilic aims to escape a run of bad luck which handed him second-round defeats at his last three events in Chennai, the Australian Open and Montpellier.
Krajicek, the 1996 Wimbledon winner, said that the presence of highly-rated German teenager Zverev and Bulgarian Dimitrov, who is 14-1 this season, was a stroke of fortune for his audience.
Both of the young guns claimed titles at the weekend, with Zverev winning in Montpellier over Richard Gasquet while Dimitrov beat Belgian David Goffin at home in Sofia.
"Zverev's here. Dimitrov is here and they both won titles," Krajicek told local media. "There are a lot of good players, highly ranked, in our field. We are all assuming Zverev (now into the top 20) will soon be in the top 10."