Brilliant Brazil striker Neymar flew into Barcelona and signed a five-year contract amid great fanfare on Monday before announcing his priority was to help his idol Lionel Messi remain the world's best player.

The 21-year-old, who is just under five years younger than Messi, will line up with the Argentine in a fearsome Barca attack next season after the Spanish champion beat rival Real Madrid in the race to lure him from Santos.

After passing medical tests and penning a deal that ties him to Barca until June 2018, Neymar told the almost 60,000 fans who had turned up to welcome him at the Nou Camp stadium that playing for the club was a dream come true.