Novak Djokovic survived a second-round scare to beat Frenchman Gilles Simon at the Monte Carlo Masters.
Simon served for the match at 5-4 in the third set but world No.2 Djokovic broke back before breaking again to secure victory in just over two and a half hours.
Djokovic, winner of the event in 2013 and 2015, forced 16 break points in the match and took six of them, but lost five of the six he faced on his own serve.
He made the breaks when they mattered though and clinched victory from his first match point to progress 6-3 3-6 7-5.
"It was a very difficult match, with many changes of momentum," Djokovic said.
"It was very tiring for me, the first clay of the season."
Sixth-seeded Frenchman Jo-Wilfried Tsonga was the major casualty of the day, losing to fellow Frenchman Adrian Mannarino 6-7 (7-6) 6-2 6-3.
Another Frenchman, 11th seed, Lucas Pouille advanced with ease with a 6-2 6-4 victory over American Ryan Harrison.
Rising Croatian star Borna Coric couldn't keep his good form going after his maiden title win in Marrakech last week. He fell to French wildcard Jeremy Chardy 7-6 (7-3) 3-6 6-3.
Others to move through to the second round included Tour veterans Feliciano Lopez and Tommy Haas.
Spaniard Lopez claimed a tight 7-6 (8-6) 7-5 victory over Russian Daniil Medvedev, while German Haas demolished Benoit Paire 6-2 6-3.
The 39-year-old Haas relieved to get a win at a tournament he hasn't played at in many, many years.
"I think 2004 was the last time I played here. Who did I lose to? Geez, I forgot...Xavier Malisse... exactly," Haas mused.
"I'm very happy about this win, very happy to get another chance to go out there again and keep working on my tennis game when it counts."
Late on in the day Belgian 10th seed David Goffin joined Djokovic in the third round with a 7-5 6-1 win over veteran Spaniard Nicolas Almagro.