Even if he somehow manages to blunt Raonic's supersonic serve and drag his battered body into the second week, a probable fourth-round confrontation with all-conquering world No 1 and defending champion Novak Djokovic awaits.
Running into Djokovic is a meeting no man wants - except Hewitt.
Turning 31 next month, the South Australian can't get enough of Melbourne Park.
"I'm always pretty excited to win any match at the Australian Open," Hewitt said after advancing when Andy Roddick retired with a hamstring injury while trailing two sets to one in the much-hyped clash between the two youngest year-ending men's world No 1s in history. "Might be more purely because a few months ago, I came back from foot surgery, wasn't even 100 per cent sure I would be able to play.
"To come here, do all the right things, I'm excited to be out there."
After three months off before Christmas, Hewitt says he is feeling better with each outing.
"It's no secret I didn't play many matches last year," he said.
"To expect to come out and play against these guys, they played right through the end until - some of them - early December, it's different on the practice court to the match court."
Today, though, is another big step.
Along with Aussie Bernard Tomic, Raonic is the hottest young prospect in men's tennis.
The Montenegro-born 21-year-old has rocketed from 154th in the rankings at the start of 2011 to 25th in the world after powering to the fourth round of the Open as a qualifier last year and then kicking on.
"I've only seen him a little bit," Hewitt said. "He played very well in San Jose and Memphis early on in the year, winning his first title in San Jose.
"He's a dangerous player. But I'll be more focusing on my game, trying to take away some of his power."
Raonic is looking forward to meeting a two-time grand slam champion.
"For me, every match, it's about imposing myself whoever I play, looking to try to dictate on the return games when I get the opportunities."
- AAP
