Last week, Nadal had extended his winning run to 12 straight after defeating Australia's Nick Kyrgios 6-2, 6-1 in what turned out to be a one-sided summit clash in Beijing.
Also on Wednesday's play, Roger Federer, the 2014 Shanghai tournament champion, worked hard for his 7-6 (4), 6-4 second round win over Diego Schwartzman of Argentina.
Federer will now lock horns with qualifier Alexandr Dolgopolov of Ukraine in his round-of-16 match. In the end, it's a good win for Federer, but his game seemed a bit rusty especially on the backhand side where the unforced errors kept flowing in out of his racket.
After Chardy's compatriot Gilles Simon beat 17-year-old Wu Yibing in the Hangzhou sensation's Masters debut on Sunday, the home crowd was hoping for some good news - and Wu Di duly delivered. "I came to realise that obviously last year", he said.
"Also tried to sit all together, I think that's a lot of fun for me, as a player, to see that because usually you only see that with soccer clubs or team sports".
It is clearly a bold strategy, but with the track record of success that Federer has, it would be brave to disagree with his thinking. The Swiss ace may be 36 but with two Majors in the calendar year, he is looking to consolidate crucial ATP ranking points and may be even eyeing that numero uno ranking.
Del Potro's victory over Zverev was his fourth over a top-10 opponent this year and the 16th seed already has an eye on making further strides next year after spending so long off the circuit due to injury during his career.
A pair of wicked forehand returns from the Swiss - one clocked at 162 km/ph - constructed a pair of break points.
No. 6 seed Grigor Dimitrov survived three match points down 3-6 in the final set breaker to deny Ryan Harrison 3-6, 6-3, 7-6 (6). "That's something that happened this year, and that's the most important thing for me". I think at 5-6 when he served that first serve, I knew he was going to come to the net.
Nadal had too much quality for 28th-ranked Fognini, breaking the Italian's opening service game on the way to the first set, and wrapping up a comfortable win in 62 minutes.