Jude Bellingham snatched Real Madrid a dramatic 3-2 Clasico win over champions Barcelona on Sunday with a "fundamental" goal to take them 11 points clear at the top of La Liga.
Real Madrid coach Carlo Ancelotti hailed the England midfielder's decisive intervention to take Los Blancos to the brink of the Spanish title.
Madrid twice came from behind with Vinicius Junior and Lucas Vazquez netting to level Andreas Christensen and Fermin Lopez strikes, before Bellingham rammed home the winner in stoppage time.
"He arrived at just the right time, he worked so hard in the game, it's been a while since he scored and today he scored a goal that could be fundamental in winning the league," said Ancelotti.
Barcelona, second, bounced back with a strong performance after their Champions League exit at the hands of Paris Saint-Germain but their last stand was demolished by Bellingham.
Madrid showed the same grit to stay in the match as they did midweek against Manchester City on the way to the final four in Europe, before Bellingham's knock-out blow left the Santiago Bernabeu crowd delighted.
Madrid's top scorer with 21 goals across all competitions, the former Borussia Dortmund man netted twice in Madrid's Clasico win over Barcelona in October and is shining in his first season in Spain at only 20 years old.
"We took a huge step towards La Liga," Vazquez, key in all three Madrid goals, told Real Madrid TV.
"We've had a very good season, we're on a very good path, now we just have to polish it off and we'll go for everything."
Madrid's penalty-saving hero against City, goalkeeper Andriy Lunin, made an early mistake to hand Barcelona the lead.
The Ukrainian strayed from his line to try and deal with a corner but got nowhere near the ball and Christensen nodded into the empty net.
However Madrid were quickly level through Vinicius, who fired over a fine chance before levelling from the spot.
The sensational Vazquez escaped Joao Cancelo far too easily and was tripped in the area by 17-year-old Barca centre-back Pau Cubarsi.
Barcelona were not deterred and made inroads down their right flank with Lamine Yamal giving Eduardo Camavinga a torrid time.
The 16-year-old starlet thought he had struck with a clever flick from a corner but Lunin pushed the ball to safety, with Barcelona arguing it had already crossed the line.
La Liga does not contract goal-line technology and using VAR the officials could not confirm the ball had completely entered the goal, so the Catalans were left frustrated.
"We deserved much more given the way we played but there's not much we can do," said Xavi.
"(Not having goal-line technology) is a disgrace."
Barcelona were dealt a blow on the stroke of half-time when midfielder Frenkie de Jong was taken off on a stretcher after hurting his ankle in a challenge by Fede Valverde.
Xavi also brought Lopez on for Christensen at the interval and it paid dividends for the coach after a slower start to the second half.
The midfielder was in the right place at the right time to finish after 69 minutes when Lunin could only parry Yamal's low effort back into danger.
However Madrid, seeking a fifth league and Champions League double, swiftly struck back when Vinicius crossed to the back post and Vazquez arrived to finish.
Marc-Andre Ter Stegen made a brilliant save to thwart Vinicius with Madrid looking for a winner to virtually wrap up their La Liga title.
Bellingham dealt the killer blow, despite largely being kept quiet by the Catalans until he appeared to emphatically decide the match in stoppage time from Vazquez's cross.
"Xavi, stay," mocked Real Madrid's fans with the Barcelona coach due to leave at the end of the season.
Earlier Atletico Madrid suffered a 2-0 defeat at Alaves to dent their chances of a top four finish and end a woeful week, following their Champions League exit.
Diego Simeone's side, fourth, lead fifth place Athletic by three points after Carlos Benavidez and Luis Rioja's strikes consigned them to defeat.
"We're in a terrible dynamic," Atletico goalkeeper Jan Oblak told DAZN.
"We have to improve and if we don't, this end to the season will be very tough."
