Andy Murray made a winning return to the ATP Tour after a month out with an elbow injury, beating Gilles Muller at the Monte Carlo Masters.
The Briton, 29, was broken in the first game of the match but soon asserted his class en route to a 7-5 7-5 win.
The world number one last played on the ATP Tour in Indian Wells on 12 March, though he contested an exhibition match against Roger Federer on 10 April.
The Scot, handed a first-round bye, meets Albert Ramos-Vinolas next.
Third seed Stan Wawrinka of Switzerland is also into round three after beating Czech Jiri Vesely 6-2 4-6 6-2.