Top-ranked Jannik Sinner overcame a brief lapse during the first set of a 6-4, 6-2 victory over Dutch qualifier Jesper De Jong in his second match back on tour in front of his home crowd at the Italia

The world No. 1 overcame a brief lapse during the first set of a 6-4, 6-2 victory over No. 93 Dutch qualifier Jesper De Jong in his second match back on tour in front of his home crowd at the Italian Open on Monday. Sinner jumped out to 4-1 but then lost his serve twice as De Jong evened the set at 4-4.

The men's world No. 1 missed several tournaments, but no Grand Slams. Here's what to know about the doping proceedings against him.