Mahut, who was involved in an epic 11-hour match against John Isner at Wimbledon in 2010, turned 30 on Saturday and was battling with a left knee injury but the only thing he received from the world number one was short shrift.
Djokovic was relentless from the baseline against Mahut, passing him virtually at will and banging back deep service returns the Frenchman had no chance of returning with his movement hindered due to heavy strapping on his knee.
"Obviously I feel for my opponent, who evidently could not move on the court," Djokovic said. "He could not get over, you know, into the rally two, three strokes.
"I think most of the people expected him to just retire the match and walk out of the court," he added, mindful of the fact two previous matches on Rod Laver Arena had lasted little more than a total of two hours.
"But he managed to stay. So all the credit for him."
Djokovic used the blue hard courts at Melbourne Park to launch a spectacular 2011 when he won three Grand Slam titles and vaulted to the world's top ranking, but he said on Saturday he felt he was playing even better this year.
"The bottom line is that I'm 24. I feel that I'm playing the best tennis of my life," Djokovic said. "I'm at the peak. So I should use every moment and enjoy my tennis."
The Serb will next meet Australian Lleyton Hewitt after the fan favourite hit back to beat big-serving Canadian Milos Raonic 4-6 6-3 7-6 (5) 6-3.
The former world number one, a wildcard in his record 16th appearance at Melbourne Park, rode a wave of emotion from a frenzied 15,000 crowd on Rod Laver Arena to rally from a set down to beat the 23rd seed.
The 30-year-old Australian sealed victory after four deuces in his final service game with a lob that Raonic could only return over his shoulder into the net and afterwards lay prone, arms and legs oustretched, on the court.
"It's tough serving out any match," said Hewitt.
"A couple of weeks ago I would have given anything to be serving to go into the second round at the Australian Open and it's hard to block that out.
"It's just another game but it's a big bloody game."
Like an old car, Hewitt took some time to get going on a cool evening and Raonic took the first set on the back of his fierce serve, which peaked at 228 kilometres per hour.
Hewitt served solidly, returned manfully and gradually drew Raonic into errors on long rallies, striking back to win the second set and setting up a dramatic third.
The pair swapped service breaks as they headed for a tiebreak, which Hewitt clinched 7-5 when a rattled Raonic, to his horror, netted a routine high forehand volley.
Hewitt knew the momentum was with him and he grabbed an early break in the fourth before defending his own serve like his life depended on it.
The French invasion of the Australian Open fourth round had got off to the perfect start when Jo-Wilfried Tsonga brushed past Portugal's Frederico Gil 6-2 6-2 6-2.
Heavy-hitter Tsonga delivered a typically power-packed performance on Hisense Arena, swatting the startled Frederico Gil out of his path 6-2 6-2 6-2 in just over 90 minutes.
"Every year and every tournament it's a bit of the same story for me. I play better and better every match," the 26-year-old said.
"Today I played well and didn't spend a lot of time on court, and it's good for the rest of the tournament."
Kei Nishikori became the first Japanese man to advance to the last 16 of the Australian Open since tennis was declared open in 1968 when the 24th seed rallied for a four-set victory over France's Julien Benneteau.
Nishikori, who is seeded for the first time at a Grand Slam tournament, had taken an early lead in the match on show court three but was unable to prevent his 30-year-old opponent from sealing the first set.
The Japanese number one, however, won the next two sets in tie-breaks before closing out the match when he broke Benneteau's serve to love to win 4-6 7-6 7-6 6-3 in three hours and 25 minutes.
Nishikori will face Tsonga in the fourth round on Monday.
"I hope we will go farther in the tournament," Gasquet said of the French contingent. "It's starting to be more and more difficult. We try our best to go further in the draw."