Real Madrid manager Jose Mourinho believes Barcelona were fortunate to win Saturday's El Clasico.
The champions bounced back from conceding the fastest goal in the fixture's history to win 3-1, replacing Real at the top of La Liga.
"Luck plays a part," Mourinho said. "When it was 1-0, we could easily have gone 2-0 up.
"Maybe under normal circumstances we would do, but Cristiano [Ronaldo] put it [a scoring chance] wide."
Madrid took the lead inside 23 seconds through Karim Benzema but Alexis Sanchez equalised before Xavi's deflected strike put Barca ahead. Cesc Fabregas completed the triumph with a diving header.
Barcelona playmaker Lionel Messi could have been sent off for a second bookable offence when, after being shown a yellow card for dissent, he escaped a second caution for a late challenge just before half-time.
"I thought Messi could have been sent off, but until I see it again I won't say more in case I'm wrong," Mourinho said.
Barcelona boss Pep Guardiola, who is yet to lose to Real in the league in seven games, was pleased with a result which took his team to the top of the table - they are level on points with Mourinho's side but have played one game more.
But he conceded there is still a long way to go in the title race.
He said: "I am delighted with the performance [but] Madrid will recover.
"To win here, you have to play a very good game and we have done that. But there is still much to do and Madrid will again be the leader if they beat Sevilla.
"There are no champions in December."