For a few seconds, Real Madrid appeared to have been handed one last escape route.

Deep into stoppage time against Real Betis, Natan brought down Vinícius Júnior and Kylian Mbappé placed the ball on the penalty spot with Madrid trailing 1-0. But Álvaro Valles guessed correctly, keeping out the Frenchman's effort before the final whistle confirmed the end of Real Madrid's perfect start to the La Liga season.

It was a dramatic end to Friday night's Matchday 4 encounter at Estadio La Cartuja in Seville, where Betis are currently playing their home matches while the Benito Villamarín undergoes renovation.

It was also the kind of ending that football neatly packages around one player: Madrid needed a goal, their biggest star was given the chance to provide it, and he failed.

Mbappé certainly had reasons to rue his night. The Frenchman had already struck the crossbar and passed up several opportunities before his stoppage-time penalty was saved as Madrid failed to score for the first time this season.

But José Mourinho looked beyond the missed spot-kick when trying to make sense of his first defeat since returning to Real Madrid.

"I can't explain it," the Portuguese coach said afterwards, and for much of the night Madrid had not played like a team heading towards defeat.

They started strongly and created two clear openings inside the first 15 minutes. Dean Huijsen was denied by Valles after an Arda Güler cross, while Madrid continued to threaten without finding a way through.

That failure to turn opportunities into goals would eventually define their evening.

Madrid had arrived in Seville having won their opening three league matches and scored four without reply against Málaga in their previous outing, with Mbappé among the scorers.

Against Betis, however, the chances kept coming without the finish. Mbappé hit the woodwork, Valles repeatedly frustrated the visitors and, when Troy Parrott finally broke the deadlock in the 81st minute after Thibaut Courtois had parried a header into his path, Madrid suddenly found themselves chasing a match they might have expected to be leading.

They appeared to have found a way back when substitute Carlos Espí produced a spectacular bicycle kick to put the ball in the net, only for the goal to be ruled out for offside after a VAR review.

Madrid were then handed another chance deep into stoppage time when Vinícius was brought down inside the area, but Mbappé's failure to convert the resulting penalty inevitably made him the face of the defeat.

The reaction among Madrid supporters reflected that frustration. His missed chances as well as the penalty were heavily criticised online, with some questioning how one of the game's most prolific scorers had failed to convert any of the opportunities that came his way.

But the debate quickly became broader than Mbappé.

Some supporters questioned Mourinho for leaving the forward on despite his difficult evening, while others pushed back against the increasingly familiar tendency to turn Madrid's attacking problems into a contest between supporters of Mbappé and Vinícius.

But Mourinho wasn't having any of that.

"When one of us goes to take a penalty, we all go together," he said of the miss.

Mourinho argued that Madrid had been dominant, created numerous scoring opportunities and forced Valles into several important saves. He said his players had given everything and insisted he had nothing to reproach them for in terms of their attitude.

Even a draw, he suggested, would have left him frustrated given what Madrid had produced.

Madrid were 'Naive'

Where Mourinho did find fault was in how Madrid handled some of the less glamorous parts of the contest.

He described his side as "naive" compared with Betis, although he was careful to explain that he was not questioning their effort or commitment.

Instead, Mourinho felt the home side had been more streetwise in their reactions to fouls and in using the atmosphere at La Cartuja to put pressure on the officials.

He pointed to an early challenge on Federico Valverde, who stayed on his feet, and contrasted Madrid's approach with what he regarded as more theatrical reactions from some Betis players.

For Mourinho, it was another example of the small details Madrid had failed to manage as well as their opponents.

He nevertheless refused to use the referee as an explanation for the defeat and remained adamant that his players had done enough with the ball to deserve considerably more.

His verdict on Betis was characteristically pointed: they had "played for a draw and hit the jackpot".

Madrid, in other words, had played enough football to win but failed in enough of the decisive moments to leave themselves vulnerable. Betis made theirs count: Parrott converted when his opportunity arrived and Valles produced the decisive intervention when Madrid were offered theirs.

An Opening for Barcelona

The result also gives Barcelona an early reason for encouragement.

Madrid had taken maximum points from their opening three games, but their first defeat means they remain on nine points after four matches rather than extending their perfect start.

Barcelona, meanwhile, have the opportunity to take advantage of their rivals' first stumble when they face Valencia on Sunday.