Barcelona, Spain (SportsNetwork.com) - Eight-time champion Rafael Nadal succumbed to fiery Italian Fabio Fognini in Thursday's third-round action at the $2.1 million Barcelona Open tennis event.

The 13th-seeded Fognini stunned the second-seeded former world No. 1 Nadal 6-4, 7-6 (8-6) on the red clay at Real Club de Tenis Barcelona.

Fognini is now 2-4 lifetime versus Nadal, with both wins coming in their last two matchups. The Italian also beat the Spaniard in a semifinal in Rio back in February.

Prior to this week, Fognini had been winless in his five previous appearances in Barcelona.

The struggling nine-time French Open king Nadal, slowed by injuries over the last 10 months, has now lost two of his last three matches and failed to reach the final in his last four tournaments since titling in Argentina on March 1.

"My play was awful and I didn't deserve to win," said Nadal.

"Fognini played better than me and deserved to win," he added. "Until I resolve the ups and downs I have had too often this season I will continue to be vulnerable."

The 28-year-old great is now 43-3 lifetime in Barcelona.

Meanwhile, top-seeded and defending champion Kei Nishikori and third-seeded four-time runner-up David Ferrer avoided upsets on Day 4. The 2014 U.S. Open runner-up Nishikori whipped 15th-seeded Colombian Santiago Giraldo 6-2, 6-1 in a rematch of last year's Barcelona final, while Ferrer handled Swedish wild card Elias Ymer 6-3, 6-4.

In other third-round action, Pablo Andujar upset fifth-seeded fellow Spaniard Feliciano Lopez 6-3, 6-4; seventh-seeded Spaniard Roberto Bautista Agut bested 10th-seeded Pablo Cuevas of Uruguay 7-6 (7-5), 6-2; ninth-seeded Tommy Robredo drilled fellow Spaniard Marcel Granollers 6-2, 6-2; 12th-seeded German Philipp Kohlschreiber foiled Frenchman Benoit Paire 6-4, 7-6 (8-6); and 14th- seeded Slovak Martin Klizan took care of Dominican Victor Estrella Burgos 6-4, 6-3. The veteran Robredo titled here in 2004 and was the Barcelona runner-up in 2006.

Friday's quarterfinals will pit Nishikori against Bautista Agut; Ferrer versus Kohlschreiber; Robredo against Klizan; and Fognini versus Andujar.

This week's champion will collect $495,000.