Karim Benzema stunning flick and a free kick from Toni Kroos saw Real Madrid complete a league Clasico double over Barcelona in soaking wet conditions on Saturday night.
A drenched Alfredo di Stefano stadium saw Benzema and Kroos put the hosts two to the good inside half an hour.
Barca hit back on the hour mark through Oscar Mingueza and the defender almost found the equaliser later on, while the Catalans had a huge penalty appeal waved away when Martin Braithwaite fell following a challenge by Ferland Mendy.
Real midfielder Casemiro was sent off in stoppage time for picking up two yellow cards in the space of a minute while Barca substitute Ilaix Moriba hit the crossbar in the fourth minute of added time.
The hosts survived the nail-biting finish to complete a sensational week after beating Liverpool 3-1 in a Champions League quarter-final first leg on Tuesday.
Zinedine Zidane's side joined Atletico Madrid on 66 points and moved top of the table, although Atletico can reclaim first place when they visit Real Betis on Sunday. Barca dropped to third on 65.
