La Toussuire - Reigning champion Vincenzo Nibali won the 19th stage of the Tour de France on Friday as Nairo Quintana clawed back time on race leader Chris Froome.
Italian Nibali went some way to rescuing what has been a difficult Tour defence by claiming a stunning solo victory on the 138km stage from Saint Jean de Maurienne to La Toussuire.
Quintana took second on the stage at 44sec but finished 30sec ahead of third-placed Froome to perhaps reignite the yellow jersey battle.
Colombian Quintana is now 2min 38sec back from the Briton ahead of Saturday's 20th stage finish on Alpe d'Huez.
But it was the return of the 'Shark of Messina' that most animated an enthralling day in the Alps.
"It has been a very difficult year, the start of the Tour was difficult for me, I had some bad luck and wasn't in the best shape," said 30-year-old Nibali.
"I only found my form at the end. This is a great victory, I'm delighted.
"The fans pushed me and motivated me, there were a lot of of Italians supporting me. This is a great win for me, for my family and for Italy."
Nibali attacked out of a group of leaders on the hors category Col du Croix de Fer with almost 60km remaining.
He reeled in lone escapee Pierre Rolland on the next climb and then dropped the Frenchman on the final ascent of La Toussire.
Having suffered badly in the Pyrenees and dropped out of overall contention, Nibali has fought his way back up to fourth following his fifth Tour stage win -- he took four stages 12 months ago on the way to the yellow jersey.
Behind him, Quintana made his move with 5.5km left on the final climb and steadily eked out a gap on Froome, who was the only rider able to react.
The 30sec gained still leaves Quintana with a huge task on Saturday's final Alpine stage but significantly it was the first time he managed to take time off Froome during the Tour.
More importantly, perhaps, Froome's Sky teammates cracked early on, showing signs of weakness in the Briton's hitherto impregnable armoury.
Alejandro Valverde remains third over all at 5min 25sec but Nibali is now only 1min 19sec off a podium finish.
Overall standings after the 19th stage of the Tour de France, a 138.0km ride from Saint Jean de Maurienne to La Toussuire on Friday:
1. Chris Froome (GBR/SKY) 78hr 37min 34sec
2. Nairo Quintana (COL/MOV) at 2min 38sec.
3. Alejandro Valverde (ESP/MOV) 5:25.
4. Vincenzo Nibali (ITA/AST) 6:44.
5. Alberto Contador (ESP/TIN) 7:56.
6. Robert Gesink (NED/LNL) 8:55.
7. Mathias Frank (SUI/IAM) 12:39.
8. Bauke Mollema (NED/TRE) 13:22.
9. Romain Bardet (FRA/ALM) 14:08.
10. Pierre Rolland (FRA/EUC) 17:27.