Barcelona [ Images ] took a giant stride towards a third straight La Liga [ Images ] title when they drew 1-1 at 10-man Real Madrid [ Images ] on Saturday to preserve their eight-point lead over their arch rivals at the top with six games left.

In a tense encounter at the Bernabeu [ Images ], the first of four clashes between the teams in three competitions in 18 days, Lionel Messi [ Images ] scored from the spot in the 53rd minute after Raul Albiol was sent off for a foul on David Villa [ Images ] in the area.

Barca looked to be cruising towards a sixth consecutive victory in the "Clasico" under coach Pep Guardiola when Dani Alves felled Marcelo and the referee awarded another penalty, converted by Cristiano Ronaldo [ Images ].

The equaliser lifted Real and their Germany [ Images ] midfielder Sami Khedira had a great chance to win the match in the final minute but shot straight at Victor Valdes [ Images ].