Del Potro scores big win over Nishikori

Juan Martin del Potro's resurgence continued as he secured a big upset victory over seventh seed Kei Nishikori at the Italian Open.

The Argentine was once one of the most promising players on Tour, before a series of injuries derailed his career. He returned to tennis in 2016 following a two-year absence and has showed several glimpses of his incredible talent.

Against Nishikori on Wednesday, Del Potro once again proved what he is capable of, as he dispatched the Japanese star 7-6 (7-4), 6-3.

The victory saw him advance into the quarter-finals for the first time in eight years, where he will take on Novak Djokovic.

Del Potro signalled his intent early, breaking in the very first game of the match, but Nishikori hit back to level the scores at 4-4 before the players traded breaks again.

Kei Nishikori

It was left to a tie-break to decide the first set, and it was Del Potro who won the points that mattered.

The second set saw the former US Open champion claim another early break for a 3-1 lead before nearly converting a match point on Nishikori's serve at 2-5.

Another opportunity arrived in the very next game, however, this time on his own serve, and Del Potro made no mistake as he sealed the deal in just under two hours.

Djokovic, meanwhile, reached the last eight after beating Roberto Bautista-Agut 6-4, 6-4, breaking the Spaniard's serve three times.

Nishikori wasn't the only high-profile exit in Rome on Thursday. American John Isner claimed another scalp in third seed Stan Wawrinka, who went down 7-6 (7-1), 6-4.

Spaniard Rafael Nadal was also in action, and continued his incredible clay-court dominance with a straightforward 6-3, 6-4 victory over Jack Sock in one hour and 21 minutes.

Nadal is chasing his fourth straight ATP Tour title this week.

Thursday's third-round results in Rome

Juan Martin Del Potro (Argentina) beat Kei Nishikori (Japan) 7-6(4) 6-3 
Novak Djokovic (Serbia) beat Roberto Bautista (Spain) 6-4 6-4           
John Isner (U.S.) beat Stan Wawrinka (Switzerland) 7-6(1) 6-4           
Milos Raonic (Canada) beat Tomas Berdych (Czech Republic) 6-3 6-2    
Marin Cilic (Croatia) beat David Goffin (Belgium) 6-3 6-4             
Alexander Zverev (Germany) beat Fabio Fognini (Italy) 6-3 6-3 
Dominic Thiem (Austria) beat Sam Querrey (U.S.) 3-6, 6-3, 7-6(7)
Rafael Nadal (Spain) beat Jack Sock (U.S.) 6-3, 6-4