Del Potro, the 2009 US Open champion, is on the comeback trail after missing eight months of last season recovering from wrist surgery.
The 22-year-old opened the season with second round losses in Sydney but has been in red hot form since, posting a 34-7 record that included wins at Delray Beach and Estoril.
“I’m doing well this season, I have beaten top 10 players, there have been many good things for me in this year,” said Del Potro, who was ranked 484th in February but has clawed his way back into the top 20.
“Of course, I’m looking forward for the next Grand Slam, it’s my favorite and it will be my first time there since 2009, so will be fantastic for my confidence.
“But it’s very tough every tournament for me after 2010. I was completely out of the circuit and now I’m trying to recover my game, my fitness, everything,” he added.
Jo-Wilfried Tsonga, seeded 13th, was the top ranked player in action. The muscular Frenchman survived a couple of wobbles before knocking out Italian Fabio Fognini 6-4 7-6 (7-0).
Swiss 14th seed Stanislas Wawrinka eased pass Argentine David Nalbandian 6-1 6-4 while Latvia’s Ernests Gulbis, riding the momentum from his hard court win in Los Angeles, rallied past former world No. 1 Juan Carlos Ferrero of Spain 3-6 6-1 7-5.
Novak Djokovic, Rafa Nadal, Roger Federer and Andy Murray, looking to win the title for a third successive time, return to action on Tuesday for the first time since Wimbledon.
In evening ceremonies Djokovic accepted the ATP No. 1 ranking trophy while Federer quietly celebrated his 30th birthday.
In Toronto, former world No. 1 Jelena Jankovic suffered a swift exit at the Toronto Cup on Monday, falling 6-1 6-3 to Germany’s Julia Goerges on a day where a pair of other top seeds fell.
France’s Marion Bartoli and Russia’s Svetlana Kuznetsova also suffered surprise first-round exits, both players eliminated by a pair of gritty qualifiers.
Goerges had not won a set in two previous meetings with the 15th seeded Jankovic but the 22-year-old German struck early and never really allowed her opponent any chance to get back in the 71-minute match.
“It’s always tough to play a player like Jelena, she’s a great fighter, great player and a former world number one so you always have to play your best,” said Goerges.
“Just go out there and fight and that’s what I did today and obviously it worked pretty well.”
Goerges, who has been hailed as the ‘new Steffi Graf’, will play the winner of Tuesday’s match between Serena Williams and Alona Bondarenko.
World No. 9 Bartoli fell 6-3 6-3 to Kazakhstan’s Galina Voskoboeva while Kuznetsova followed her out of the $2 million tournament when she was upset 4-6 6-4 6-3 by Romania’s Simona Halep.
Bartoli had trouble moving around the court and getting her usually strong backhand working against Voskoboeva.
“When you commit so many mistakes like I did today, it’s really hard to win a match,” Bartoli told reporters.
“It was really like my game was not at the level I’m supposed to play regarding my ranking. That was the main problem.”
Samantha Stosur of Australia overcame a slow start to get past Japan’s Ayumi Morita 4-6 6-2 6-3.
