Melbourne: Gilles Simon admitted he "got pretty lucky" after recovering from an ankle injury which left him on crutches just days ago to win a marathon first-round match at the Australian Open.

Simon, who hobbled out of the Kooyong Classic last Friday, ground down Daniel Brands over five sets and four-and-a-half hours in temperatures of around 40 Celsius (104 Fahrenheit) late on Tuesday.

The 6-7 (4/7), 6-4, 3-6, 6-3, 16-14 win, culminating in a 30-game final set, clocked in as the longest on a sweltering day two in which players, fans and ball kids all suffered in the heat.

But Simon, the 18th seed from France, said conditions suited him to a tee as he was able to remain static on his painful ankle and simply look for winners.

"It was on the limit to go on court. It`s always a tough decision to make. I think this time I got pretty lucky," he said.

"I said, `Okay, it`s not easy that everybody saw me with the crutches. If I just go and I`m (playing) ridiculous, I guess no one`s going to talk good about me.`"

Simon, who said he was in significant pain, sent down 32 aces, including 16 in the nearly two-hour final set. Out of 461 rallies in the match, not one was longer than four shots.

"I just looked at the guy I`m facing. I know the guy has a good serve. I know he`s weaker from the baseline, so I know I can serve full. I mean, I`ve never served that many aces in a match," he said.

"I know it`s 40 degrees. Okay, you never know, you just try, anything can happen. I tried, and then I got lucky."

Simon, who will next play Marin Cilic, added: "I played a lot of serve and volley. I felt I couldn`t run from the baseline, so I was trying to keep it short to break to rhythm, to give no rhythm to this match."