Germany coach Joachim Loew said the defending World Cup champions played “very badly” in Sunday’s 1-0 loss to Mexico, warning that the shock defeat left them with little margin for error in their remaining group games.

Germany’s preparations ahead of the World Cup were plagued by poor results and controversy, and their problems were magnified in Moscow as they crashed to their first defeat in the opening game of a World Cup since 1982.

Hirving Lozano’s 35th-minute strike at the Luzhniki Stadium earned Mexico just the second win over Germany in history, as Loew’s side paid the price for a dismal first half.

“In the first half we played very badly,” Loew said. “We weren’t able to impose our usual way of playing, our attacking and passing was not effective.”

“It’s disappointing to have lost the first match,” he added. “It’s a situation we’re not used to at all. In many previous tournaments we’ve always won the first match but we have to accept it.”

Germany’s proud record of never being eliminated in the group stage at a World Cup is already in danger.

And if they finish runners-up in Group F, Germany could be on course to face Brazil in a daunting second-round match-up.

Germany face Sweden in their next match on June 23 in Sochi before concluding their group campaign four days later in Kazan against South Korea.

“The team has experience dealing with losses. It goes without saying that the next match will be decisive for us, we have to win it,” Loew said.

“We will not change our gameplan. If we play out our ideas then we have players who are able to deliver.

“We need to focus on our strong points, which we haven’t been able to do in our last couple of games.

“We have three matches in the group phase and we have ample opportunities to correct this result.”

Loew started eight of the nine 2014 World Cup winners in his squad, with Mesut Ozil returning from a knee injury and Manuel Neuer back in goal following his lengthy absence.

- ‘Best goal’ -

Jerome Boateng’s build-up to the finals was also hampered by a groin injury, and the Bayern Munich centre-back found himself exposed often as Mexico’s speed was a constant threat on the counter-attack.

After a remarkably open start, Mexico struck the decisive blow 10 minutes before half-time after Sami Khedira lost possession in the opposition half.

Javier Hernandez triggered a lightning break before finding a charging Lozano, who cut inside a covering Ozil and lashed low inside Neuer’s near post to spark deafening roars from the sizeable Mexico support.

“I think it’s definitely the best goal I’ve ever scored in my life, we all dream of playing in the World Cup,” PSV Eindhoven forward Lozano said.

“I don’t know if it’s the biggest win in (Mexico’s) history but doubtless it is one of the biggest for sure.

“It’s great to start on the right foot when you’re playing against the world champions.”

Germany hit back, Toni Kroos rattling the crossbar with a 25-yard free-kick that needed the fingertips of a scrambling Ochoa to keep it out, but Mexico barely clung on to their advantage.

At 39, Rafael Marquez became just the third player to feature at five World Cups as he was brought for the final 15 minutes to fortify Mexico’s defence.

A frenetic finale saw substitute Julian Brandt smack the outside of the post with a thunderous effort from 20 yards.

One desperate last attack then had Neuer come up for a corner before Mexico closed out an unforgettable triumph.

“I think it’s a milestone for Mexican football,” said Mexico coach Juan Carlos Osorio.

“We played with bravery when it was needed and defended with all our hearts, I think we need to give the credit where it’s due and that’s to the players.”