Dubai - Roger Federer, who lost his Australian Open title to Novak Djokovic last month, moved to within one win of a possible rematch with the Serb as the two rivals accelerated into the semi-finals of the Dubai Open Thursday.
Federer, a 16-time Grand Slam winner, won a colourful match full of daring shot-making against Sergiy Stakhovsky, the world number 43 from the Ukraine, 6-3, 6-4.
Djokovic, in the best form of his career while winning the first Grand Slam tournament of the year, had to work unexpectedly hard for a second successive day to beat Florian Mayer, the world number 38 from Germany, 7-5, 6-1.
Djokovic was puzzled early on by Mayer's unusual combinations of slice and net attack, and went 3-5 down before finding some answers and advancing.
Federer also went a break down before getting into his stride, and later had an important piece of luck when Stakhovsky was denied a break back for 4-4 in the second set by a line call which Hawkeye showed to be incorrect.
But Federer revelled in the open, attacking game which the talented Stakhovsky created and which allowed opportunities for the maestro to produce his most inspired tennis.
Some of it happened at love-40 in the third game, when Federer was at risk of dropping serve a second time - only for him to turn it around with a service winner and four aces.
Asked whether he had served four aces in a row before, Federer said: "I have, yes," and even looked slightly embarrassed when the crowd laughed at that.
Another humourous exchange occurred when Federer led by a set and 3-1, when a man bellowed "come on Stakhovsky!"
Stakhovsky responded with a cracking ace and double-handed gesture towards the spectator, as though offering a gift. When there followed a call of "come on Federer", Stakhovsky gave a pantomime glare.
Sometimes he matched Federer's brilliance, but rarely with similar consistency. Federer closed the match out with a game in which he managed a delicately dinked passing shot despite galloping full tilt for a drop shot.
Federer seemed pleased to complete the task in straight sets. "I try not to waste energy," he admitted later. "You want to give yourself a chance of winning the trophy."
To do that he may face a Djokovic in a determined frame of mind, even though the defending champion has yet to perform at his best here.
It was fully 40 minutes before Djokovic got a handle on Mayer's unusual mixtures and subtleties. During this phase the best that could be said for Djokovic was that he showed no signs of panicking.
That paid dividends. For when Mayer came to close the set out at 5-4, he morphed into a different man, full of doubts and mistakes.
Worse still, when Mayer had to serve to save the set, at 5-6, he produced two double faults and lost the game to love. After that Djokovic was more himself, extending his comeback to a winning sequence of eleven games out of 12.
"Tennis is a mental game and a lot of things depend on momentum," said Djokovic. "So if you can use the momentum and make him feel you are on top of him, it works."
But to reach the final Djokovic will need a revenge. He faces Tomas Berdych, the man who beat him on route to the Wimbledon final in July, and who progressed with a 7-5, 6-4 win against Philipp Petzschner, the German whose world ranking of 73 belies his talent.
To keep alive his chances of a fifth Dubai Open title Federer will have to get past Richard Gasquet, the Switzerland-based Frenchman who as a teenager once beat him in Monte Carlo.
Gasquet earned a rematch by winning an all-French encounter against his Davis Cup colleague Gilles Simon, 5-7, 6-2, 6-4, and reaching his first semi-final since Metz in September.
Simon has now failed to beat Gasquet in all their five encounters on the main ATP World Tour. This though was the closest he has come, the contest hingeing on a service break in the seventh game of the final set, courtesy of two typically stunning backhand drives down the line from Gasquet.
"It was difficult because Gilles knows my game well and we are friends," said Gasquet. "Federer has beaten me many times since I beat him, but I am not the only one, so that's okay."
Quarter-final results (x denotes seeds):-
Richard Gasquet (FRA) bt Gilles Simon (FRA) 5-7, 6-2, 6-4
Roger Federer (SUI x1) bt Sergiy Stakhovsky (UKR) 6-3, 6-4
Novak Djokovic (SRB x2) bt Florian Mayer (GER) 7-5, 6-1
Tomas Berdych (CZEx3) bt Philipp Petzschner (GER) 7-5, 6-4