Francisco “Isco” Alarcon, who had been sidelined by former coach Santiago Solari, and Gareth Bale, a reserve before Zidane’s return, scored to help Madrid end its four-game losing streak at the Santiago Bernabeu Stadium.
Zidane’s revamped lineup also included Marcelo, another player who had succeeded under the French coach but did not play often with Solari.
The win moved Madrid within two points of second-place Atletico Madrid, which visits Athletic Bilbao later. Barcelona, which plays at Real Betis on Sunday, is seven points in front of Atletico.
Zidane received an ovation from the crowd when his name was announced before the match, and there was an upbeat atmosphere again following demoralizing home losses.
Madrid lost to Barcelona in the Copa del Rey and the Spanish league, and to Ajax in the round of 16 in the Champions League — results that virtually ended the team’s hopes of winning a trophy this season. It had also lost at home to Girona in the league.
Isco netted from close range in the 62nd minute after Asensio fed Karim Benzema inside the area and the French striker set up the scorer in front of goal. Isco was cheered by the crowd when he was substituted a few moments after the goal, his first of the year.
Bale sealed victory with a shot from inside the area in the 77th.
Zidane led Madrid to nine titles in his first stint, including three straight in the Champions League, but quit at the end of last season, saying the club needed a change.
He was rehired on Monday to replace Solari, who wasn’t able to keep the team on track in its first season without Cristiano Ronaldo.
Celta, which needed points to have a chance of escaping the relegation zone, has lost 10 of its last 12 matches in all competitions. It is 18th in the 20-team standings with 25 points from 28 matches.
Benzema had a goal disallowed just before halftime because of a foul by Bale, while Luka Modric’s goal in the second half was disallowed on video review because Madrid defender Raphael Varane was offside.
JOY FOR ALAVES
Alaves moved closer to the final Champions League spot with a 3-1 win at last-place Huesca, moving within a point of fourth-place Getafe, which visits Valencia on Sunday.
Argentine striker Jonathan Calleri scored twice and Swedish forward John Guidetti added another for Alaves, which is unbeaten in six games.