Madrid: Cristiano Ronaldo bagged a share of the spoils for Real Madrid from the penalty spot on Saturday after Lionel Messi had netted a spotkick of his own for a 1-1 draw which keeps Barcelona on course for the Spanish title.
Ronaldo's effort denied Barca a win which would have all but ended the title race as the two rivals met in the first of four "Clasico" clashes inside three weeks which will decide the destination of this season's silverware.
Messi and Ronaldo scored their 30th league goals of the season as Barcelona stayed on course for glory after their encounter at the Santiago Bernabeu which left the visitors, chasing a third successive league title, with an eight-point cushion over Madrid with six games left.
Messi opened the scoring with a 53rd-minute penalty that left Real down to ten men with centre-back Raul Albiol sent off for conceding the kick - but Madrid levelled on 82 minutes through Ronaldo.
The draw brought an end to Barcelona's five straight wins over their rivals and ended coach Pep Guardiola's 100 percent record in the fixture.
"A draw at the Bernabeu is a good result and I am happy with how we played, although maybe we could have done better at 1-0," said Guardiola. "I don't think we are league champions (yet) as we have to play against teams that are still fighting for their lives."
Real boss Jose Mourinho had seen Barcelona thump his side 5-0 at Camp Nou and still waits for his first win in the fixture, but will have another shot on Wednesday when Madrid face Barcelona in the Kings Cup final.
After that the bitter rivals will also go head to head in the Champions League semis.
"It was very even with 11 players against 11," said Mourinho afterwards. "It was two teams that respect each other and know how powerful the other one is.
"It was mission impossible to play with ten men for so long against a team that are, without doubt, the best team in the world in possession."
Goalkeeper Iker Casillas explained: "Our aim was to win but it wasn't easy to get the draw playing with ten men."
Mourinho opted for a more muscular midfield with defender Pepe playing alongside Sami Khedira, while the more creative Mesut Ozil dropped to the substitutes bench.
Barcelona sprung a big surprise with captain Carles Puyol starting in central defence in his first game since being sidelined with a knee injury in mid-January.
A sea of white flags created an intimidating atmosphere at the Bernabeu and Madrid were pressing hard to disrupt Barcelona's fluid passing game.
It was Mourinho's 50th competitive game in charge of Madrid and his side were sitting deep and playing on the counter attack, which didn't sit too well with the home fans.
Four minutes after the interval Ronaldo won, and then took a free-kick from the edge of the penalty and thumped the left hand post with Victor Valdes well beaten.
It was a warning but Barcelona then won a penalty on 53 minutes with Albiol pulling down Villa and receiving a red card to hit the hosts with a double punishment.
Messi lifted his penalty past Casillas to put Barca ahead and score against a Mourinho team for the first time in his career.
Xavi hit the crossbar on the hour mark for Barca with Casillas beaten and minutes later Pepe headed against the post as Madrid rallied.
Substitute Emmanuel Adebayor had a good chance for Real on 69 minutes but his poor control with his head let him down at the decisive moment.
With eight minutes to go Marcelo was felled by Brazilian compatriot Dani Alves in the box and Ronaldo made no mistake with the spot-kick smashing it into the top corner for his first Clasico goal.
Earlier, Spanish forward Roberto Soldado made it seven goals in his last three league games as Valencia won 3-0 at bottom side Almeria to consolidate third place.
Soldado headed in a Jeremy Mathieu cross five minutes after the break to notch his 13th league goal of the campaign before Lithuanian Marius Stankevicius and Jordi Alba sealed Valencia's 10th away win of the season.
Valencia move nine points ahead of fourth-placed Villarreal as they chase the third and final automatic Champions League berth.