Mason, OH (SportsNetwork.com) - Four-time runner-up Novak Djokovic went by way of an upset, while Australian Open champion Stan Wawrinka and two-time Cincinnati titlist Andy Murray were a pair of come-from-behind third-round winners Thursday at the $3 million Western & Southern Open tennis event.

Spanish veteran Tommy Robredo, seeded 16th this week, tackled the world No. 1 Djokovic 7-6 (8-6), 7-5 in 1 hour, 44 minutes.

Djokovic, who lost in the third round last week at the Masters event in Toronto. still needs this Cincy title to complete a career Golden Masters, or all of the Masters 1000 championships.

Robredo is now 2-6 lifetime versus the Wimbledon champion and U.S. and French Open runner-up Djokovic, who beat the Spaniard at the Miami Masters earlier this season.

While Djokovic stumbled, Roger Federer managed to advance in his third-round match. The second seed and 17-time Grand Slam champ prevailed in a tough three-set bout with Gael Monfils, with Federer handing the Frenchman a 6-4, 4-6, 6-3 defeat.

Federer, the runner-up at last week's Canadian Masters, boasts a record five Cincinnati titles.

The Swiss legend will next take on Murray in a blockbuster quarterfinal encounter after the eighth-seeded former world No. 2 fought back to best 11th-seeded American favorite John Isner 6-7 (3-7), 6-4, 7-6 (7-2) in 2 hours, 23 minutes. The ace-filled match featured 21 from Isner and 14 for Murray, who saved two match points in the 12th game of the third set before advancing.

Isner was last year's Cincinnati runner-up to Rafael Nadal, while the former U.S. Open champion Murray titled here in 2008 and 2011.

Wawrinka, meanwhile, dropped the first set against 14th-seeded Croat Marin Cilic before charging back for a 3-6, 6-0, 6-1 victory on the hardcourts at Lindner Family Tennis Center. The third-seeded Wawrinka dropped just three service points in an emphatic second set and closed out the victory in 83 minutes.

The hard-hitting Swiss also beat Cilic in Monte Carlo this year en route to his first-ever Masters title.

Wawrinka's quarterfinal opponent on Friday will be capable Frenchman Julien Benneteau, who got past struggling 6-foot-8 Pole Jerzy Janowicz 7-5, 6-1 on Day 5.

Also on Thursday, fifth-seeded Canadian Milos Raonic launched 30 aces before outlasting two-time NCAA singles champion Steve Johnson, of the United States, 6-7 (7-9), 6-3, 7-6 (7-4), while 15th-seeded fiery Italian Fabio Fognini came back to beat Taiwan's Yen-Hsun Lu 3-6, 6-3, 6-3. The recent Washington, D.C., champion Raonic will face Fognini on Friday.

Robredo will face sixth seed David Ferrer, who cruised to a 7-5, 6-0 decision over Mikhail Youzhny.

The winner of this Masters and U.S. Open Series tournament will earn $638,850.