The top seed and defending champion, El Aynaoui saved one match point before posting a 4-6, 6-3, 7-5 victory over Nicolas Massu of Chile. It was his third straight three-set win this week for El Aynaoui, who is 6-0 in three-set matches since beginning last year's campaign for the title.
"What can I say after a match like that," said the 30-year-old, who has played some marathon matches this year, including a memorable five-set loss to Andy Roddick in Australian Open quarterfinals. "It was a tough match but it's especially gratifying after twice losing this year after holding match points."
Arazi, the 1997 champion, rallied past Olivier Mutis of France, 3-6, 7-6 (11-9), 6-4. He fought off three match points in the second-set tiebreaker.
"When I was down, I didn't really have much hope to come back, but in that sixth game of the third set when Mutis made some errors, I also had some fantastic points and a great shot to get back to 4-2," Arazi said. "That was the turning point in the match. At 4-2, I really felt like I was back in it."
Both matches featured boisterous behavior from the Moroccan crowd, which whistled on Mutis' serve when he had match points and made noises during points.
"I'm glad I had the support of the crowd but sometimes it's too much and it works against me," El Aynaoui said.
Mutis was bothered by the fans but did not use it as an excuse.
"The match was hell because of the public, but I didn't lose because of the crowd, I lost because I made mistakes," the Frenchman said.
El Aynaoui has won both his previous meetings with Arazi.
"I hope it's going to be a good match tomorrow against Hicham," he said. "I'm good friends with him, I have nothing to lose. I hope the crowd will be a little calmer and enjoy the tennis as it is supposed to be enjoyed."
Fourth seed Dominik Hrbaty of Slovakia overcame Argentine qualifier Federico Browne, 6-7 (5-7), 6-3, 6-0. He will take on Julien Boutter of France in the semifinals.
Boutter beat Brazilian Flavio Saretta, 7-5, 7-6 (7-5), to reach his first ATP semifinal since he made the last four here a year ago. He is 6-2 lifetime at this event.