Top-ranked Jannik Sinner passed a big test in his return from a three-month doping ban, beating accomplished clay-court player Francisco Cerundolo 7-6 (2), 6-3 on Tuesday to reach the Italian Open quarterfinals.

World number one Jannik Sinner said the support and friendship he received from Jack Draper during his three-month ban for a doping violation gave him the positive energy he needed to make it through a difficult period.

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