Fifth seed Del Potro, a quarter-finalist in 2009 and 2017 at the Internazionali BNL d’Italia, triumphed 7-5, 6-3 in one hour and 42 minutes on Pietrangeli for a third-round test against ninth seed David Goffin of Belgium.
The 19-year-old Tsitsipas got off to a 4-2 advantage, courtesy of a break in the third game, when Del Potro struck an in-out forehand that hit the net and landed wide. However, Tsitsipas gifted the break back with a double fault at 3-4. Del Potro soon seized control and at 6-5, he finally converted his fifth set point chance on Tsitsipas’ serve with a deep crosscourt backhand that the Greek mis-timed.
Del Potro broke Tsitsipas for a 3-1 lead in the second set – in a run of 17 out of 25 points – and finished the match with a forehand winner down the line. The Argentine struck 24 out of 37 winners off his forehand wing.
Del Potro, who is now 23-5 on the season, returned to the Top 10 in the ATP Rankings for the first time since August 2014 on 15 January 2018.
He has already lifted back-to-back trophies at the Abierto Mexicano Telcel presentado por HSBC (d. Anderson) and the BNP Paribas Open – his first ATP World Tour Masters 1000 crown (d. Federer). His 15-match winning streak ended at the hands of John Isner in the Miami Open presented by Itau semi-finals.