The number 18 seed ruined Hewitt's Melbourne dream with an inspired 6-7, 7-6, 7-6, 6-4 fourth-round on Monday but he will need to produce more of the same magic to prevent Roddick from reaching his first Grand Slam semi-final.
Roddick, who retired with a sprained ankle during his second-round match here last year, pulled off a minor miracle of his own in the fourth round, coming from two sets down to beat Russian Davis Cup hero Mikhail Youzhny 6-7, 3-6, 7-5, 6-3, 6-2.
The 20-year-old, one of the so-called "Generation Next" of American tennis, reached the last eight of the U.S. Open in 2001 and 2002 -- both times losing to the eventual champion. But he has yet to reproduce that form in an overseas Grand Slam.
Roddick, though, warned that he is ready to make the breakthrough in 2003.
"As far as (grand) slams go, I definitely want to make a dent in one this year. The more you play, the more comfortable you are in this situation," he said. "No one is really paying attention to me, which I don't mind."
However, the spotlight will be firmly focused on the young American when he takes on El Aynaoui, who is quite capable of knocking off another top 10 player, especially if he can serve as well as he did against Hewitt.
The 31-year-old fired down 33 aces and was never broken in a remarkable performance at Rod Laver Arena that had Hewitt screaming at himself in frustration.
There is no less at stake in the other quarter-final on Wednesday between 10th seed David Nalbandian and Rainer Schuettler, the number 31 seed.
Nalbandian, the 2002 Wimbledon runner-up, has gone quietly about his business, reaching the last eight with a tough five-sets win over Swiss number six seed Roger Federer on Monday night.
But the Argentine is likely to find the super-fit Schuettler a hard nut to crack. The German will be relatively fresh after having played just 10 sets in the tournament so far.
Schuettler, appearing in his first grand slam quarter-final, won his first two matches in straight sets and had a walkover against injured number three seed Marat Safin before his 6-3, 6-4, 1-6, 6-3 win over James Blake in the fourth round.
