MELBOURNE - Roger Federer's trademark poise under pressure has propelled him into his 10th straight Australian Open semi-final after a high-class five-set battle with power-packed Frenchman Jo-Wilfried Tsonga.
The athletic Muhammad Ali look-alike went shot for shot with the four-time Open champion throughout Wednesday night's quarter-final, with only a few critical points separating them as the Swiss great won 7-6 (7-4) 4-6 7-6 (7-4) 3-6 6-3.
It booked the second seed an enticing semi-final match-up with third seed Andy Murray on Friday night.
The Scot beat Federer in last year's Olympic Games gold medal match, after Federer had downed Murray in the Wimbledon final to claim his 17th major title.
Federer had not lost a set or even a service game previously in the tournament.
But Tsonga's mix of big serves, big shots, delicate touch at the net and court speed troubled the Swiss enormously as he dropped serve five times for the match.
In the second and fourth sets that proved decisive but in the first and third Federer's poise in the tiebreakers was invaluable.
In the first-set tiebreaker an over-rule fault call on Tsonga's first serve of the game proved critical as Tsonga lost that point, giving Federer an advantage which he maintained throughout.
In the third-set breaker, Federer produced an exquisite down-the-line backhand to grab a mini-break and 6-4 lead, then clinched it on his first set point.
Tsonga, who became the first man to beat Federer from two sets to love down in a grand slam match in the 2011 Wimbledon quarter-finals, refused to buckle or temper his aggressive game.
He roared through the fourth set, breaking Federer's serve twice.
A crucial unforced error on break point in the fourth game of the fifth set proved costly.
But Tsonga fought to the end, saving four match points on his own serve at 2-5, the third of those with a spectacular lunging volley, forcing Federer to serve it out.
Meanwhile daytime warrior Andy Murray felt compelled to book a rare practice session under lights after powering into the Australian Open semi-finals at the expense of outclassed Frenchman Jeremy Chardy on Wednesday.
All of Murray's first five matches to date at the 2013 Open have been in the heat of the day - and all have ended in straight-sets victories.
But his semi-final against Roger Federer will be the feature match on Friday night at Rod Laver Arena, with Federer's quarter-final win over Jo-Wilfried Tsonga his fourth straight night match in that arena.
While that encounter was taking place, the third-seeded Murray was getting his eye in with a hit-out at Hisense Arena.