Angry Barcelona fans last night called for coach Louis van Gaal to be replaced after Sevilla claimed a 3-0 win in the Nou Camp.
Francisco Casquero put third-bottom Sevilla ahead from the penalty spot in the fourth minute and Mariano Toedtli made it 2-0 with a header after 76 minutes.
Toedtli then bundled in the third two minutes from the end to cap a horrendous night for the home side.
Barcelona supporters waved white handkerchiefs after the second goal, telling Van Gaal that they want him out.
The Dutchman returned for his second spell at Barcelona in the summer, and while their Champions League form has been outstanding, in the Primera Liga they have won four and lost six of their 14 matches so far.
Stefano Fiore was the Lazio hero with two goals as Roberto Mancini's team fought back to beat Juventus 2-1 and prove, if proof was still needed, that they are in the title hunt.
The former Udinese winger doubled his season's tally with goals in the 35th and 50th minutes.
Pavel Nedved, a former Lazio player, had put Juve ahead in the 34th minute, but their lead was short-lived.
Lazio moved to second place, a point behind leaders AC Milan, and a point ahead of Inter Milan.
Juventus, last season's champions, remain fifth.
VfB Stuttgart stayed on course for a place in Europe next season with a 2-1 Bundesliga win at VfL Wolfsburg yesterday.
The victory left Stuttgart, who knocked out Club Bruges on Thursday for a spot in fourth round of the UEFA Cup, in fifth place in the German first division entering the winter break.
Crisis-hit Kaiserslautern recorded their third league victory of the season with a much-needed 2-1 win over Hertha Berlin in the other match played yesterday.
And in France's Ligue 1, bottom club Montpellier scored in the last minute to draw with Lyon yesterday and ensure Marseille stayed top of the table.
Lyon could have reclaimed the league leadership with a win, and that seemed the likely outcome after Eric Carriere's 56th-minute goal. But Abdoulaye Cisse scored in the 90th minute to grab a point which could prove vital in their bid to avoid relegation.