La Liga: Robert Lewandowski's double secures first victory for new Barcelona manager Hansi Flick

Robert Lewandowski scored two goals for Hansi Flick's Barcelona as they fought their way to a 2-1 victory against Valencia in their first La Liga match of the season on Saturday.

The German coach celebrated his first competitive match at the helm with three points as Barca came from behind against Ruben Baraja's solid Valencia side.

Hugo Duro sent the hosts ahead after 44 minutes but veteran Polish striker Lewandowski levelled from close range before the break and netted a penalty early in the second half.

With champions Real Madrid, led by new superstar Kylian Mbappe, in action on Sunday at Real Mallorca, Barcelona started their bid to steal the crown with an impressive result at Valencia's rowdy Mestalla stadium.

ALSO READ: Bayer Leverkusen claim maiden German Super Cup title with win over Stuttgart

Barca were without key players, including Frenkie de Jong, Gavi and Ronald Araujo and Flick selected three 17-year-olds in his starting line-up.

They were Spain's Euro 2024 star Lamine Yamal, whose father was stabbed earlier this week in a violent attack, Pau Cubarsi and midfielder Marc Bernal, the latter making his debut.

"In the second half I think we played much better and with three or four very young players -- I think this match is very important, to win at the beginning of the season, especially at this stadium in Valencia, it's very difficult," Lewandowski told Movistar.

"My aim is always to score goals, I don't know how many goals by the end of the season, but it is very important for me that as today was the first game, (I got) goals for confidence."

Barcelona's summer signing Dani Olmo is not yet registered to play and Flick said the playmaker still needs to get up to speed in terms of fitness.

The coach was happier with his team's second-half display than their performance before the break.

"The second half was much better than the first half (where) we made a lot of mistakes," Flick told Movistar. "We came back at the end of the first half and in the second half, we did much better."

An even first half burst into life as the break beckoned after the teams managed to create few clear chances in the first 40 minutes.

Duro nodded the best of them over the bar from a corner, while Valencia goalkeeper Giorgi Mamardashvili saved a fierce Raphinha drive.

Valencia took the lead in the 44th minute, with Duro nodding home Diego Lopez's cross after losing Inigo Martinez, who played him onside.

Disclaimer: This story has been published from a news agency feed with minimal edits to adhere to web's style guide. The headline may have been changed to better reflect the content of the story or to make it more suitable for the web audience.