Barcelona failed to score the second despite a hatful of chances and Cadiz punished them with a late equaliser, Alex Fernandez converting from the spot after a wild swing from Clement Lenglet.
Kylian Mbappe ripped Barcelona apart on Tuesday by scoring a stunning hat-trick in a 4-1 rout to put Paris Saint-Germain on the brink of the Champions League quarter-finals.
Defender David Alaba joined Bayern Munich's academy in 2008, made his Bundesliga debut in March 2010 and has so far won 26 trophies with the club.
From nurturing the next generation of Barcelona talents to confronting one of Europe's richest, most ambitious clubs, the fork in the road for Lionel Messi's future is becoming clear.
Victory means Barcelona trail Atletico Madrid by eight points again after the leaders temporarily pulled 11 clear thanks to a hard-fought 2-1 win over Granada earlier on Saturday.
UEFA Champions League: Neymar's absence in the fixture vs Barcelona is a big blow for PSG, who are also without winger Angel Di Maria.
Argentinian forward Angel Di Maria will miss the first leg of Paris Saint-Germain's Champions League last 16 match at Barcelona, coach Mauricio Pochettino said on Tuesday.
Luis Suarez shows no sign of letting up, the Uruguayan now with 11 goals in his last nine games and 16 for the season.
Ronald Koeman said on Friday he believes Lionel Messi is happy again at Barcelona but admits only the Argentina forward will decide his future at the club.
Lionel Messi will take a call on his Barcelona future after the end of the 2020-21 season, said a report.