Wawrinka was barely tested against the No. 100-ranked Ilhan, striking 34 winners and saving the only two break points he faced.
In a breakthrough 2014 season, Wawrinka claimed his first Grand Slam title, reached a career-high ranking of No. 3 and helped Roger Federer win the Davis Cup for Switzerland.
"It's great, bringing me a lot of memories from last year," Wawrinka said of his return to Rod Laver Arena. "It was great to come back here feeling happy, happy with my game."
Two other men widely considered to be in the next generation of major winners advanced in straight sets, with No. 5 Kei Nishikori beating Nicolas Almagro, 6-4, 7-6 (1), 6-2, and No. 8 Milos Raonic firing 30 aces in a 7-6 (3), 7-6 (3), 6-3 win against Illya Marchenko.
No. 12 Feliciano Lopez struggled past American wild-card entry Denis Kudla, 3-6, 6-2, 4-6, 6-2, 10-8; No. 18 Gilles Simon beat Robin Haase, 6-1, 6-3, 6-4; and No. 19 John Isner beat Taiwanese qualifier Jimmy Wang, 7-6 (5), 6-4, 6-4. No. 16 Fabio Fognini lost in four sets to Alejando Gonzalez.
Nishikori, returning to Grand Slam action for the first time since his run to the U.S. Open final, dropped his opening service game but recovered the break quickly and weathered a difficult opening match.
Nishikori is coming off a big year in 2014, when he became the first Asian man to reach a Grand Slam singles final. He's determined to go one better and win a major.
Two-time champion Victoria Azarenka continued her comeback from a foot injury with a convincing 6-3, 6-2 win over Sloane Stephens and will next have to play U.S. Open finalist Caroline Wozniacki, who beat 18-year-old Taylor Townsend, 7-6 (1), 6-2.
Limited to just nine tournaments last year, Azarenka has seen her ranking fall to No. 44 and she is unseeded at a Grand Slam for the first time since the 2007 U.S. Open.