The true No 1: Roger Federer celebrates beating Novak Djokovic in the French Open semi-finalsNovak Djokovic's brilliant winning streak met a dramatic, murky end when Roger Federer announced he was far from finished.
At 9.37pm and with an overnight suspension due, the Swiss brought Roland Garros to its feet by becoming the first man to beat Djokovic this year as he inflicted on him a 7-6, 6-3, 3-6, 7-6 defeat.
Federer was the last man to overcome the Serb back in November at the O2 Arena, and now he may have put a stop to his ambitions of becoming world No 1.
If Nadal wins Sunday's final he can retain the position threatened by Djokovic's 41 straight victories, a sequence which is one fewer than John McEnroe's run in 1984.
Mutual respect: Federer embraces Djokovic after an enthralling match of the highest quality
What a sight: The Swiss maestro guides another mesmeric backhand down the lineWith the start of play ridiculously put back an hour, they looked like gatecrashing women's finals day when Federer, 30 in August, was twice a break down towards the end of the fourth set.
Yet he broke back both times and in the tiebreak, played through badly fading light, pumped down an 18th ace to clinch it 7-5.
Federer has been desperate to show he is not a spent force at a time when he has been shunted out of the top two and the Nadal-Djokovic rivalry is all the rage. It is a powerful motivating force, as his form all fortnight has demonstrated.
When you're hot, you're hot: Djokovic came into the match on the back of a 43-match winning streak 
Tough day at the office: Djokovic feels the strain as he loses the first two setsThe confident Djokovic nonetheless forced two set points at 5-4 in the opener before the Swiss went on to edge the tiebreak 7-5.
Then we saw vintage Federer as, roared on by a crowd who have always adored him, he produced superbly fluent groundstrokes to blast through the second set 6-3 before the inevitable Djokovic comeback.
But Federer reached his first Grand Slam final since beating Andy Murray in Melbourne nearly 18 months ago.
A shattered Djokovic immediately pulled out of next week's Aegon Championships at Queen's.
You said it: Federer fans show their support for the 16-time grand slam champion
Celebrity spotting: Actress Salma Hayek was in the stands to watch Federer's brilliant display
FEDERER VS DJOKOVIC - ROLLAND GARROS 2011 | FULL HIGHLIGHTS | OFFICIAL HD
source: dailymail