British number three seed Andy Murray eased into the next round with a 6-2, 6-2, 6-1 win over Argentina's Juan Igancio Chela and a match-up against either Germany's Mischa Zverev or Potito Starace of Italy.
Murray, one of the few men capable of pouncing should four-time champion Rafael Nadal or Roger Federer slip-up, needed just an hour and 45 minutes to see off Chela, a former quarter-finalist whose ranking has slumped to 205.
"It was a very good win. Chela's a tough player. I needed to play well and I did," said the Scotsman who unleashed 55 winners. I lost my first service game but after that I was happy with the way I played."
Hewitt and Safin, both former world number ones and with two Grand Slam titles each, enjoyed contrasting victories.
Hewitt survived a world record 55-ace barrage from giant Croatian Ivo Karlovic to claim a 6-7 (1/7), 6-7 (4/7), 7-6 (7/4), 6-4, 6-3 win which consumed almost four hours.
It was the fifth time in his career that the 28-year-old Australian, twice a quarter-finalist in Paris, had come back from a two-set deficit.
Karlovic's ace-count was a world record, beating the previous best of 51 he shared with Sweden's Joachim Johansson set at Wimbledon in 2005; both men still lost.
Hewitt, now ranked 50 and who underwent hip surgery in August last year, will face Andrey Golubev of Kazakhstan for a place in the third round where four-time champion Rafael Nadal is a likely opponent.
"To play Karlovic on any surface is hard especially when his ace-count is up in the 50s," said Hewitt, of a man who famously defeated him in the first round at Wimbledon in 2003 when the Australian was defending champion.
"After losing the tiebreakers it's more of a mental battle. You have to hang in there and go the distance."
Karlovic's career record in five-set matches remains at 0-11.
Safin, a semi-finalist in 2002 and playing his 11th and last French Open before retiring, eased past French wildcard Alexandre Sidorenko 6-4, 6-4, 6-4.
"I still have months to go. I have plenty of tennis yet to play," said the 29-year-old Safin.
There there was to be no fairytale return for 2004 champion Gaston Gaudio who took last year off to escape the grind of the tour.
The Argentine wildcard, the last winner before Nadal took charge, lost 6-3, 6-4, 6-1 to Czech 18th seed Radek Stepanek.
From Eurosport
