Bernard Tomic has taken the easy way into the second round of the Thailand Open, with opponent Ivo Karlovic withdrawing with a back injury on Tuesday.
Fellow Australian Marinko Matosevic joined Tomic as a winner as he crushed Thai wild card Wishaya Trongcharoenchaikul 6-1, 6-1.
Tomic, playing his first match since helping Australia back into the Davis Cup World Group with a victory over Poland, struggled early before gaining the upper hand and was leading the towering Croatian 6-7 (3-7), 6-4, 4-2 when the injury became unmanageable.
Tomic, winner of the Sydney International in January, spent nearly two hours battling the 34-year-old Karlovic, who dropped out in the third set as his injury problems set in.
Karlovic, a former Bangkok quarter-finalist like Tomic, lost an opening match for the second straight week after going out in Metz, France.
Tomic improved to 24-16 on the season, moving onto a match with 2012 finalist Gilles Simon, the French fourth seed who comes to Asia after winning the Metz trophy.
Meanwhile, eighth-seeded Lukas Rosol smashed 16 aces as he continued an upturn in form with a three-set win over Poland's Lukasz Kubot.
The giant Czech, who has endured a dismal run since claiming his breakthrough ATP title in April, beat Kubot 6-3, 3-6, 7-6 (7-2).
The 196-cm Rosol relied on his booming serve on the Bangkok hard court to secure passage into the second round.
But the close match had to be settled by a third-set tiebreaker, where Rosol took a 5-0 lead, before claiming victory with the first of four match points as Wimbledon quarter-finalist Kubot hit the net with a backhand return.
"The third set was not easy," said Rosol. "He was playing tough, aggressive tennis. I was lucky to win it, but I'm really glad I did. It's great to be in the second round."
The world No.46 said he was coming back to form after a dreadful few months following his win in Bucharest.
"I had so many bad matches and zero confidence. But I've been putting in a lot of hard work and maybe things are starting to change. I feel like I'm coming back.
"Everyone is practising so hard, there are no easy matches," said the 31-year-old, who was a key member of the Czech team that swatted away Argentina in the semi-finals of the Davis Cup earlier this month.
His summer had been one to forget with eight consecutive opening round losses, starting at Wimbledon where he failed to emulate his heroics of 2012 when he knocked out Rafael Nadal in an epic five-setter.
But after reaching the quarters last week in St Petersburg, Rosol said his hard work on the training courts was paying off.
Both Rosol and Kubot were making their Bangkok debuts on Tuesday.
Elsewhere, Slovak Lukas Lacko moved into the second round by beating Colombia's Alejandro Falla 6-3, 6-2.
It was more bad news for Colombia when Japan's Go Soeda defeated Santiago Giraldo 3-6, 6-1, 6-2.