Two of Australia's last remaining hopes bowed out of the Sydney International on Wednesday, while another was forced to withdraw with an abdominal strain that threatens his maiden Australian Open appearance.
Seventeen-year-old prodigy Alex De Minaur was forced to pull the pin after losing the first set to Andrey Kuznetsov in Sydney on Wednesday night.
Scorched: Jordan Thompson plays a backhand against Philipp Kohlschreiber.Credit:Getty Images
De Minaur struggled with an abdominal complain that has cast doubt over his ability to accept the wildcard into next week's grand slam in Melbourne.
Jordan Thompson was beaten in straight sets by fifth seed Philipp Kohlschreiber, while Matthew Barton lost to sixth seed Gilles Muller in a see-sawing three-set affair.
Heat break: Matthew Barton takes a breather.Credit:Getty Images
Playing in scorching conditions, the Australian pair were outclassed and outmatched by their more fancied opponents.
However, Thompson will take solace from the fact he was able to stick with the world No. 32 for much of the contest before losing 7-5, 6-4.
"It was tough. He played well. I thought I served pretty well most of the match, but just in key moments he made some pretty good returns," Thompson said.
"It was just really tricky conditions. It was a little bit swirly at times, 39 degrees, and the balls were flying. Yeah, I think it was pretty solid for the conditions."
Thompson has had a strong start to the season, defeating former world No.3 David Ferrer in singles before claiming the doubles title with Thanasi Kokkinakis in Brisbane last week.
He is pleased with the way he's been playing and confident that the time spent on court over the past couple of weeks holds him in good stead for next week's Australian Open.
"I guess my movement, my fitness and today, in particular, I served pretty well. I'm not unhappy with anything, but I guess those things I'm most happy with," he said.
"It's prepared me for the Aussie Open. The key to the start of the year before a grand slam is get some matches on. I have done well."
Earlier in the day, world No.198 Barton's run in Sydney came to a heartbreaking end, broken in the final game of the third set on a controversial line call, losing 6-1, 3-6, 6-4.
Barton was slow out of the blocks, as he struggled to find his range with his first serve. However, he quickly hit back to claim the second set as Muller fried in the 40-degree heat.
Muller admitted that he considered throwing in the towel after losing the second set, however he pushed on and ultimately claimed the match as the mercury nudged 41 degrees.
Up next for the world No.34 is second seed Pablo Cuevas, who defeated Nicholas Mahut 6-4, 2-6, 6-2.