(CNN) -- World number three Andy Murray and defending women's champion Ana Ivanovic are both through to the second round of the French Open, after the year's second grand slam event got off the mark in blazing temperatures at Roland Garros.
Defending champion Ana Ivanovic showed no signs of her recent knee injury on her French Open return.
Murray impressively eased past Argentina's Juan Igancio Chela -- a former quarterfinalist -- 6-2 6-2 6-1 in just one hour, 45 minutes to secure a match against either Germany's Mischa Zverev or Potito Starace of Italy.
"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, after the match. "I lost my first service game but after that I was happy with the way I played."
On a day of few surprises, the match of the day involved former world number one Lleyton Hewitt, who recovered from losing the opening two sets to defeat giant Croatian 6-7 6-7 7-6 6-4 6-3.
It was the fifth time in his career that the 28-year-old Australian, twice a quarterfinalist in Paris, had come back from a two-set deficit -- and he did so despite Karlovic sending down a world record 55 aces, bettering his own mark by four.
Hewitt, world ranked 50 after hip surgery last August, will face Andrey Golubev of Kazakhstan for a place in the third round where four-time champion Rafael Nadal is a likely opponent.
Meanwhile, Marat Safin, a semifinalist in 2002 and playing his 11th and final French Open before retiring, eased past French wildcard Alexandre Sidorenko 6-4 6-4 6-4.
There was to be no fairytale return for 2004 champion Gaston Gaudio, who took 2008 off to escape the grind of the ATP tour.
The Argentine wildcard, the last winner before Nadal took charge, lost 6-3 6-4 6-1 to Czech 18th seed Radek Stepanek.
In the women's draw, Ivanovic clinched a 7-6 6-3 win over Italy's world number 44 Sara Errani, showing few signs of the knee injury which kept her out of the Madrid Open.
The 21-year-old, seeded eighth despite being the defending champion, will play either Thai veteran Tamarine Tanasugarn or Camille Pin of France for a place in the third round.
China's Li Na, the women's 25th seed, had the honor of becoming the first player to reach the second round thanks to a 6-4 6-2 win over Poland's Marta Domachowska. The 26-year-old Li now meets Switzerland's Timea Bacsinszky.
Also making progress in the women's draw were Belarussian ninth seed Victoria Azarenka and Russian 11th seed Nadia Petrova, who will face Maria Sharapova if the former world number one gets past the first round on Monday.