World number three Novak Djokovic made a confident start to his Roland Garros campaign, sealing a straightforward victory over Aleksandar Kovacevic.
Djokovic, a two-time champion in Paris, defeated the 114nd-ranked American 6-3 6-2 7-6 (7-1).
He powered through the first two sets before losing focus in the third-set, prompting Kovacevic to rally from 3-5 to force a tie-break.
Despite the turnaround, the Serb held firm on the world's biggest clay court to complete the win, converting five of his 12 breakpoints and hitting 41 winners.
"I played well in the first two sets but then I missed opportunities and lost a little focus," said Djokovic, who is the second player in the Open Era to win 65 consecutive first-round matches at Grand Slam events.
"But it is also a sign of Aleks' level, which was getting better.
"When you get to a Grand Slam it is not the opponent who gives you the victory, you have to earn it."
The 36-year-old, whose target is a record 23rd men's Grand Slam singles title, will now face Hungary's Marton Fucsovics in the second round.