A virtuoso performance from Roger Federer saw him progress to the semi-finals of the ATP World Tour Finals after a 6-3 6-0 win over great rival Rafael Nadal.
The reigning champion controlled the first set before raising his game further in the second to breeze past Nadal in just over an hour at the O2 Arena in London.
The victory, which included an array of brilliant winners, means world number four Federer cannot fall out of the top two places in Group B.
Second seed Nadal, meanwhile, can still progress to the last four if he wins his final match of the round-robin stage against Jo-Wilfried Tsonga.
"It's a very surprising result, I guess we can't always live up to our expectations and I've definitely seen Rafa play better, but I've also definitely played worse," Federer told Sky Sports after the match.
"I'm happy it went so well and I wish Rafa all the best for the rest of the group. For me it (the tournament) continues which is fantastic. I'm very excited about the way I played tonight."
He added: "Every day is different, it's a challenge to come out and play your best every day but today was one of those days, so I'm very pleased."
Rivalry
Despite Nadal holding the overall edge in the pair's famous rivalry, Federer went into the match having won all three of their previous meetings on hard courts.
The duo traded comfortable holds early on but Federer pounced in the sixth game, earning three break points before wrapping the game up as Nadal cracked in a lengthy rally.
The crowd roared their appreciation, with the Swiss flags waving again shortly afterwards when another Federer forehand winner gave him the first set.
Nadal needed to up his game urgently but instead suffered another setback in the first game of the second set as Federer drilled another sublime forehand winner down the line to secure a second break of serve.
The Spaniard, whose fitness is being questioned by some, simply could not cope with the 30-year-old's aggression and Federer made it four games in a row with another break of serve.
Nadal has built his success against Federer on his ability to pin the Swiss on his backhand but the Spaniard's forehand does not have the same bite and kick on indoor courts and his shots were being swatted away.
The French Open champion was struggling simply to get on the board in the second set but in the end was not able to prevent being blanked and Federer wrapped up his first love set against the Spaniard for four and a half years - a fitting symbol of his dominance.
