Lionel Messi scored a last-gasp equaliser to complete a hat-trick and earn 10-man Barcelona a thrilling 3-3 home draw with arch-rivals Real Madrid on Saturday.
The 19-year-old Argentine snapped up a pass from Ronaldinho on the edge of the area, beat two defenders and steered a low shot into the far corner in the final minute at the Nou Camp.
Messi and Real Madrid striker Ruud van Nistelrooy had each netted twice in a frantic first half hour, but the home side were dealt a blow when fullback Oleguer was sent off in the 45th minute.
Barca spent most of the second period on the ropes as Real tried to take advantage of their numerical superiority and the visitors looked to have secured victory when defender Sergio Ramos headed in 17 minutes from time.
"Scoring three goals at the Nou Camp and not coming away with the win is almost unimaginable," Real's sporting director Predrag Mijatovic told television channel La Sexta.
"But this shows that we are still alive and there is a long way to go yet."
Frank Rijkaard's side returned to the top of the Primera Liga, level on 50 points with Sevilla, who visit lowly Gimnastic on Sunday.
Real remain fourth, five points adrift of the leaders and one behind Valencia.
Fabio Capello's team made a dream start when van Nistelrooy scored after five minutes, the Dutchman curling a shot round keeper Victor Valdes from the edge of the area.
LOW SHOT
Barca levelled six minutes later when Messi guided a low shot past keeper Iker Casillas after Samuel Eto'o had slipped the ball behind the back four.
The home fans barely had time to celebrate before van Nistelrooy restored Real's lead, registering his 14th goal of the season with a penalty after Guti's foot was clipped by Oleguer.
Barca, though, found gaps in Real's defence with ease and Messi made it 2-2 when he smashed the ball into the roof of the net after Casillas had blocked an angled shot from Ronaldinho.
The home team's momentum was halted when Oleguer was sent off for a second caution after a needless foul on Fernando Gago.
Van Nistelrooy had several good chances to complete his hat-trick in the second half only to be denied by a string of reaction saves from Valdes.
Nevertheless, Real looked to have gained only their second league win at Barca in 24 years when Ramos flicked a header over Valdes from a Guti free-kick.
But the livewire Messi had the final word in the last minute.
In Saturday's other match, Uruguay striker Diego Forlan and Denmark international Jon Dahl Tomasson handed Villarreal a 2-0 win at struggling Levante.