The world number 165 from Argentina, who was a semi-finalist in 2013 in what was his last appearance at the tournament, next faces either French 32nd seed Lucas Pouille or Donald Young of the United States.
Del Potro is playing in his first major since the Australian Open in 2014 after undergoing three wrist surgeries.
“It feels amazing, it’s a great sensation,” said 27-year-old Del Potro, the 2009 US Open champion.
“I enjoyed the crowd. It’s an incredible feeling, that’s why my hands are still shaking.
“I feel alive again. After sitting at home for two years, this feels like a second or third career,” added the former world number four.
source: sports.inquirer.net