It took the 20-year-old American a minute short of five hours to make his 11-year advantage count against the valiant Moroccan, Roddick sealing a 4-6, 7-6, 4-6, 6-4, 21-19 victory to reach his first Grand Slam semi-final.
While Roddick is one of the new breed of tennis players, more rock star than racket wielder, El Aynaoui belongs to a gentler era. Quietly spoken, non-confrontational and with a ready smile on his face he prefers to construct points thoughtfully, always ready to throw in the gentle, angled shot.
The contest was always going to throw up a contrast in styles, but that it produced such incredible drama was a bonus.
The match statistics read like the index of a tennis record book but the real story was etched on the faces of the two combatants, weary but aware they had been involved in something special.
"Younes is a class act. I am extremely humbled by this victory," Roddick said, shoulders stooped and wiping sweat from his spiked hair.
"My previous longest match was about three hours 45 and I almost had to be carried off after that.
REALLY SPECIAL
"It was really special playing that fifth set. The crowd was awesome, played a great part in keeping us on our feet out there."
That 21-19 fifth set was the longest ever recorded in men's singles at the Australian Open. It was also the longest fifth set in any Grand Slam men's singles match since tennis turned professional in 1968.
In terms of games, the match was the longest since tiebreaks were introduced to this event in 1971, easily eclipsing the 73 Yannick Noah needed to beat Bahamian Roger Smith in 1988.
That anyone had to lose was a pity.
El Aynaoui, an amiable father of two, played the match of his life two days ago to beat world number one Lleyton Hewitt.
On Wednesday night he played the match of his life again, twice leading by a set and at one stage holding a match point, but this time he came up against
"Andy just kept a high level," El Aynaoui said. "I was waiting for an opportunity but he just kept a high level throughout and I congratulate him. That's all I can do."
"Even though I lost I am happy."
Roddick, the youngest Melbourne semi-finalist for 11 years, will face Germany's Rainer Schuettler - also into his first grand slam semi-final -- after the German ousted Wimbledon runner-up David Nalbandian 6-3 5-7 6-1 6-0.
DRAMATIC TENNIS
While dramatic tennis dominated the men's singles, the main action in the women's singles was conducted by Serena Williams off court.
The top seed reached her first Australian Open semi-final and Kim Clijsters made it two in a row as the pair set up a mouth-watering match-up at Melbourne Park.
Williams pounded fellow American Meghann Shaughnessy into submission 6-2 6-2 while Clijsters ousted eighth seed Anastasia Myskina 6-2 6-4.
Thursday's semi-final between Serena and the Belgian fourth is one to fire the imagination, adding an edge to the top half of the women's draw.
Just minutes after swamping Shaughnessy, Williams pondered her next match and was clearly a little rattled by all the talk surrounding the in-form Clijsters.
The last time the pair met on a major stage Clijsters won to lift the WTA Championships last November, but suggestions of revenge for Serena provoked an unusual response.
"Vengeance belongs to God...I am just here to play tennis," she said.
"Sure the gap is closing (between the Williams sisters and the chasing pack), but quite frankly I am tired of answering these questions."
Clijsters, who has won her last three tournaments, is again likely to ask some serious questions of Serena.
"I'm sitting here in the semi-final and I haven't lost a set yet," the Belgian said. "I'm feeling very fresh still.
"Against Venus or Serena you'll have to run a lot so it is definitely a good sign not to have played too many sets... spent too much time on court."
