It took the Scot four sets to see off Russian Andrey Kuznetsov
Britain's Andy Murray is safely through to the second round at the French Open.
The world number one got past Russian Andrey Kuznetsov in four sets - 6-4 4-6 6-2 6-0.
Last year's French Open runner-up has struggled for form so far this year, but was took his time to break down the world number 73 on Tuesday.
Kuznetsov broke Murray's serve four times, but the Scot pulled away at the start of the third set to join Novak Djokovic and Rafael Nadal in the next round.
Earlier, Stan Wawrinka progressed to the second round with a straight-sets victory over Slovakia's Jozef Kovalik.
The former champion claimed a convincing victory - 6-2 7-6 (8-6) 6-3.
Argentine Juan Martin del Potro overcame compatriot Guido Pella 6-2 6-1 6-4. The victory was significant as Del Potro continues to find form after a wrist injury which has plagued his career in recent years. The victory was his first match at the French Open since 2012.
Alexander Zverev suffered an early exit after losing 6-4 3-6 6-4 6-2 to Spain's Fernando Verdasco.
But there are no more British players involved in the women's draw - following Johanna Konta's shock exit.
The seventh seed lost in three sets to Chinese Taipei's Su-Wei Hsieh - who's ranked outside the world's top 100.