Novak Djokovic played through the pain of a shoulder problem to win his opening match at the Paris Masters and collect a $1.6m (£1m) Tour bonus.
The Serb eased past Croatian Ivan Dodig 6-4 6-3 to make the last 16.
"I think it is obvious that I am not quite at the top of my game," he admitted after his win.
"I'm taking things quite slowly, step by step, knowing that my form will improve."
After missing the Masters event in Shanghai with a persistent shoulder problem, the 24-year-old suffered a recurrence in his semi-final defeat to world number 35 Kei Nishikori in Basle.
Djokovic insisted he had considered only his fitness, and not his finances, before opting to play in the French capital.
"It was really funny to see how people are coming up with this story," he added.
"I even heard that I would get on court and just play one game to get this money - I mean this is ridiculous.
"We are all athletes, this is our job and we are all playing to get paid. I don't see what is unusual about that.
"On the other hand, I came here to compete and because I want to play a tournament.
"If I know I am physically in good enough condition to compete I will compete, if I don't, I will not compete. It is as simple as that. There is nothing else that can affect my decision."
Djokovic was clinical in securing a single break in each set to see off the challenge of Dodig in 91 minutes.
Although he committed 10 unforced errors and two double-faults in the first set, he produced a sublime behind-the-back forehand early in the second as he shook off some of his rustiness.
World number four Roger Federer, who has never been to the final of the indoor event, overcame France's Adrian Mannarino 6-2 6-3.
Federer will face French opposition again in the third round in the form of Richard Gasquet, while Djokovic will play Viktor Troicki after his compatriot and Davis Cup team-mate beat Ukraine's Sergiy Stakhovsky 6-4 6-4.
Janko Tipsarevic, a third member of the Serbia team that beat France to clinch the country's first Davis Cup title in December, thrashed American Alex Bogomolov 6-0 6-1.
Spanish fourth seed David Ferrer eliminated home crowd favourite Nicolas Mahut 6-4 6-4.
John Isner, Mahut's opponent in their epic first-round match at Wimbledon in 2010, progressed with a win over Igor Kunitsyn of Russia, while Ukrainian Alexandr Dolgopolov battled past Philipp Kohlschreiber in a second-set tie-break.