Jose Mourinho's second spell in charge of Real Madrid began with a last-gasp 2-1 victory at Espanyol in LaLiga on Saturday, with substitute Carlos Espi pouncing in the 90th minute to grab the winner.
Jude Bellingham opened the scoring in Los Blancos' opening fixture of the season, and new signing Espi secured the points at the death after Alex Calatrava had levelled against Mourinho's star-studded team.
"I think that we deserved to win but that Espanyol didn't deserve to lose," Mourinho told reporters.
"They didn't have any players at the World Cup and have been working together for a long time, and you could see that."
Back in charge of Madrid 13 years after leaving, Portuguese veteran Mourinho must bring the dressing room under control after the chaos of last season, and end Spanish champions Barcelona's domestic dominance.
Mourinho started with superstars Kylian Mbappe, Vinicius Junior and Bellingham, as well as handing debuts to Bernardo Silva, Denzel Dumfries and Ibrahima Konate.
Bellingham had an excellent first season at Madrid after arriving from Borussia Dortmund but the subsequent two were disappointing, both for him and the club, who failed to win a major trophy in either.
Mourinho installed him in attacking midfield with licence to roam and the former Birmingham man was heavily involved before his goal as Madrid probed.
The England international netted the first of Mourinho's second era at the club, heading home Arda Guler's dangerous crossed free-kick.
Espanyol threatened midway through the first half as Madrid goalkeeper Thibaut Courtois beat away Clemens Riedel's drive and Roberto Fernandez hooked over shortly afterwards.
Madrid did not heed the warning and Espanyol levelled in the 30th minute, Calatrava slotting home Javi Hernandez's cut-back after a fine team move.
INTENSE BATTLE
Espanyol stopper Marko Dmitrovic made a good save to stop Mbappe after he got in behind on the right of the area.
The French forward, LaLiga's top scorer in both of his two seasons at the club, was not at his lethal best in front of goal.
On the left flank Vinicius had little impact, beyond winning a series of fouls from Espanyol players who were determined to shut him down by any means.
"Vini is not a saint, but what they do to im is too much, it started in the first minute, I think it's something systemic, it's done in a systemic way," said Mourinho.
"First I hack him, then you, then me, then you, if I get a yellow then you do it. I have a yellow so I go off, and someone comes on without a yellow... it's frustrating for him."
Mourinho sent on two more new arrivals in the form of record signing Yan Diomande and Marc Cucurella as Madrid sought a winner in the final 25 minutes.
Federico Valverde hit the outside of the post with a low effort from the edge of the box as Espanyol dug deep to deny Madrid clear chances.
However in the 90th minute Madrid found the goal they needed when former Levante striker Espi, the lowest profile of Los Blancos' summer purchases, capitalised on a loose ball in the box and fired home.
"We carried out our plan well and then let in that goal at the end," said Calatrava.
"That we conceded was a gut-punch, because we worked hard until the end."
Earlier, Sevilla won 3-1 at Athletic Bilbao and Valencia and Celta Vigo drew 0-0.
On Sunday champions Barcelona play their first game of the season at Elche, while Atletico Madrid host Villarreal.