Isco struck at the death to send Real Madrid six points clear of Barcelona at the top of La Liga after twice coming from behind to beat Sporting Gijon 3-2 on Saturday.
Madrid can all but secure a first league title in five years with victory when they host Barca next weekend.
But not for the first time this season they needed a late show after Duje Cop and Mikel Vesga put Sporting in front early in both halves.
Isco’s fine individual effort and a towering header from Alvaro Morata ensured neither lead lasted more than a few minutes.
And Isco sealed the comeback when he drilled home from the edge of the box.
“I am happy for him. He has the character to do what he did today,” said Madrid boss Zinedine Zidane.
The Spanish international is yet to agree a new contract with his current deal expiring at the end of next season.
And Zidane insists he wants Isco to stay despite his lack of starts and interest from Barcelona.
“You know what I think of Isco, he is a player I like a lot and his place is here.”
Barca can close the gap back to three points when they host Real Sociedad later on Saturday.
Zidane made nine changes from the side that beat Bayern Munich in the first leg of their Champions League quarter-final in midweek.
Cristiano Ronaldo and Karim Benzema were left out of the squad entirely alongside the injured Gareth Bale, while Toni Kroos, Luka Modric and Marcelo had to settle for a place on the bench.
“I feel like I am unfair with those that don’t play, but it is always going to happen,” added Zidane.
“There are 24 players that can play in all positions. It is the difficult part of this job.”
Cop missed a late penalty with the chance to snatch a draw when the sides last met in November.
However, the Croatian made amends when he finished off a lovely Sporting move by volleying home Vesga’s scooped pass to put Sporting in front after 14 minutes.
The lead lasted just three minutes as Real responded with a wonder goal of their own.
Isco received Lucas Vazquez’s pass inside a crowded penalty area but somehow dribbled past two Sporting defenders before curling the ball into the top corner.
Sporting retook the lead five minutes into the second half as Vesga looped a measured header into the far corner.
Once again, though, Sporting’s defensive deficiencies were quickly exploited by the European champions as Morata towered above his marker to head home Danilo’s cross.
Madrid then peppered the Sporting goal, but didn’t make the breakthrough until the final minute as Isco’s effort from the edge of the area had too much power for Cuellar.
Atletico Madrid warmed up for the second leg of their Champions League quarter-final against Leicester City with a comfortable 3-0 win over rock bottom Osasuna despite missing two penalties in the same game for the second time this season.
Coach Diego Simeone also left out a number of his first-team regulars with top scorer Antoine Griezmann left on the bench for the full 90 minutes.
Yannick Carrasco’s low strike and back-post header put Atletico comfortably ahead either side of half-time.
Left-back Filipe Luis then added his third goal in five games.
However, Atletico’s problems from the spot continued as they have now failed to score any of their last six penalties in La Liga.
Carrasco was denied his hat-trick by a fine save from Salvatore Sirigu before the Italian ‘keeper made an even better stop to deny Thomas Partey seconds later.
Victory takes Atletico four points clear of Sevilla in third.