Lionel Messi
Messi played his first professional match at 16 years old on 16 November 2003 against Porto. He played the 2003-04 season with the Barcelona B team. He was promoted to the A team for the 2004-05 season, and made his league debut on 16 October 2004 against Espanyol as a substitute. He made his league debut at age 17, and became the youngest player to play for Barcelona's first team in an official competition. He scored his first professional goal on 1 May 2005 against Albacete Balompie from a sublime assist by Ronaldinho. The goal made him the youngest-ever scorer for the club at that time. Barcelona won the La Liga that season for the first time in 6 years, and won the league for a second time in a row along with the Spanish Super Cup and UEFA Champions League in 2006.