Carlo Ancelotti said Jude Bellingham's late strike in Sunday's 3-2 clasico win over Barcelona could be "fundamental" to Real Madrid winning the Spanish league.
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.
Victory at the Bernabeu moved Madrid 11 points clear at the top of La Liga with only six games remaining to significantly loosen reigning champions Barcelona's grip on the title.
"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," Ancelotti said of Bellingham.
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 winner sent the majority of the Bernabeu into raptures.
England midfielder Bellingham, 20, has enjoyed a standout debut season in the Spanish capital with Sunday's clasico winner his 21st in all competitions.
"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 use goal-line technology and using VAR the officials could not confirm the entire ball had crossed the line, so the Catalans were left frustrated.
"We deserved much more given the way we played but there's not much we can do," said Barca head coach Xavi, adding that 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.
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.
