The tournament, a warm-up event for Wimbledon, helped launch Sharapova's fledgling career when she won it in 2004, aged just 17. Three weeks later she beat Serena Williams in the Wimbledon final.
"I'm coming off a really long layover, and it's so great to be back on court that you try to cherish every single moment,'' said the former top-ranked player. "I have such great memories of this little stadium.''
Returning after 10 months out due to shoulder surgery, Sharapova adapted well to the breezy and cool conditions, hitting ambitious ground strokes and serving solidly with her new truncated action.
The former top-ranked Russian next plays Alexa Glatch of the United States, who beat Bethanie Mattek-Sands, the ninth seeded American 7-6, 6-3.
First XI: Badges of honor
Nadal returns to defend Queen’s Club title
