German second seed Alexander Zverev suffered an early exit at the China Open as he went down 7-6(4) 2-6 6-4 to Tunisias Malek Jaziri on Thursday.
The world number five appeared to have righted the ship after losing the opener in a tiebreak but paid the price for failing to convert his opportunities.
Jaziri, 34, executed an audacious tweener to win a point at 2-5 down in the second set and although Zverev still levelled he went onto claim his third victory over a top five opponent this season.
Up next for the world number 61 is a first Tour meeting with Nikoloz Basilashvili. The Georgian, ranked 34 in the world, overcame Spains Fernando Verdasco 7-6(3) 6-4.
Italys Fabio Fognini thumped Andrey Rublev 6-4 6-3 and will take on world number 45 Marton Fucsovics for the first time.
Hungarian Fucsovics beat surprise French Open semi-finalist Marco Cecchinato of Italy 6-4 6-2.
Its going to be a tough match because he (Fucsovics) is great, he played really well today, Fognini, currently ranked 11th in the race for the ATP World Tour Finals, said.
Top seed Juan Martin del Potro, who has already clinched his place in next months season-ending tournament in London, will meet Serbias Filip Krajinovic on Friday.
Briton Kyle Edmund takes on Dusan Lajovic in another last-eight clash.
Source: NAN