Roger Federer and Rafael Nadal were both made to work hard to ensure the latest chapter of their rivalry will be played out in the quarter-finals of the Western & Southern Open in Cincinnati.
Defending champion Federer survived what appeared to be another impending early tournament exit by raising his game to beat Tommy Haas, while fourth seed Nadal was pushed to a third set by rising star Grigor Dimitrov before prevailing in three sets.
The Swiss fifth seed has endured a difficult season, following up his only title win in Halle with a second-round defeat to Sergiy Stakhovsky at Wimbledon before slipping up in both Hamburg and on home soil at Gstaad.
After struggling with a larger prototype racket, the 32-year-old switched back to his favoured Wilson this week and the move paid dividends despite a quick 6-1 first-set raid from Germany's Haas.
Federer struggled in the second set, too, but steadily found the edge he needed on his serve to close out a 1-6 7-5 6-3 win and another date with Nadal.
The Spaniard appeared to be cruising at a set and a break up, before Bulgarian Dimitrov secured two breaks in quick succession to take the match into a decider.
Nadal broke early in the third, though, and never let the advantage slip.
He looked forward to facing Federer again, saying: "We played so many times for very important things. That makes every match very special.
"The combination of styles makes the matches very interesting. I hope to be ready for that."
The top two seeds, Novak Djokovic and Andy Murray, had life considerably more easy - though third seed David Ferrer was beaten.
Djokovic dispatched David Goffin 6-2 6-0 in just 51 minutes and will next face American John Isner, who dispatched 12th seed Milos Raonic 6-4 7-6 (7/4).
Murray, meanwhile, beat France's Julien Benneteau 6-2 6-2 to set up a quarter-final with Tomas Berdych, a 6-3 6-0 winner over Tommy Robredo.
Ferrer was upset by unseeded Russian Dmitry Tursunov, slipping to a 6-2 6-4 defeat.
Seventh seed Juan Martin Del Potro dropped a set but closed out a 6-4 1-6 6-4 over Feliciano Lopez to complete the quarter-final line-up.
The top two seeds in the women's draw progressed as Serena Williams and Victoria Azarenka sealed straight-sets wins.
Williams was a 6-4 6-1 win over Germany's Mona Barthel and will next face Simona Halep.
The Romanian continued her good form, following up the win over Marion Bartoli which sent the Wimbledon champion into retirement with a 6-4 4-6 6-2 victory over 11th seed Sam Stosur.
Second seed Victoria Azarenka sealed a comfortable 6-3 6-4 victory over Magdalena Rybarikova to set up a match against Caroline Wozniacki, a 3-6 6-2 6-3 winner over Petra Kvitova.
Li Na remained in contention to defend her title by ousting Angelique Kerber 6-4 6-4 but fourth seed Agnieszka Radwanska showed her credentials with a one-sided 6-0 6-2 dismissal of Elena Vesnina.
Roberta Vinci beat her fellow Italian and doubles partner Sara Errani 6-4 6-3 to book a face-off with Jelena Jankovic, who was given a tough workout by home hopeful Sloane Stephens on her way to a 3-6 7-5 7-5 win.