Hewitt, 17, won in his home town last year but conceded that he felt the burden of expectation on him when he faced the 35th-ranked German.
"I felt a fair bit of pressure going out there today," he said, admitting he faced a difficult progression, with the dual US Open winner and top seed Pat Rafter of Australia and former world No 1 Jim Courier among this year's lineup. A year ago, Hewitt beat Andre Agassi and countryman Jason Stoltenberg to become, at 550, the lowest ranked singles winner in ATP tour history, finishing the year ranked 113th.
Earlier, the former French Open champion Gustavo Kuerten, Slovakia's Dominik Hrbaty, Stoltenberg and fellow Australians Michael Tebbutt and Scott Draper advanced to the second round as courtside temperature hovered at around 40 degrees Celsius for much of the day. Hrbaty celebrated his 21st birthday with a 4-6 6-1 7-5 upset of the eighth seed, Mariano Puerta of Argentina.
As a balmy evening brought some relief, Sweden's Thomas Enqvist, rejuvenated after a foot injury cut short his 1998 season, fought back from a disappointing first set to beat the Australian Mark Woodforde 0-6 6-4 6-4.
The intense heat was forecast to continue today when Rafter meets Japan's Takao Suzuki and Courier plays Slava Dosedel, of the Czech Republic. Rafter's hopes of rising from fourth to No 1 this year were boosted at the weekend when the current incumbent, Pete Sampras, pulled out of the Australian Open.
Stoltenberg overwhelmed Arnaud Di Pasquale of France in the heat to win 6-1 6-4 but predicted a bright future for the French teenager, who jumped more than 500 places to 81st in 1998. "I think he is a player we will see a lot of," Stoltenberg said. Draper had a tougher battle against the American Justin Gimelstob before forcing the second set to a tie-break and then winning, 3-6 7-6 6-3.
The defending champion Ai Sugiyama of Japan survived a tough test in the first round of the Australian women's hardcourt championships. Sugiyama, the fourth seed, proved too strong for Corina Morariu of the United States, winning 6-2 6-7 6-3 at the Hope Island club on Queensland's Gold Coast. She next faces France's Sarah Pitkowski, a 6-3 6-2 winner over Australia's Alicia Molik.