San Sebastian (Spain), Jan 15 (IANS): FC Barcelona strengthened their lead in the Spanish top division football rankings after battling back from a two-goal deficit to trounce Real Sociedad 4-2 on their home turf, where they had not won in more than 10 years.

The Catalans had not managed a La Liga victory at Anoeta Stadium -- in the Basque region -- since 2007, and early on it looked like that unfortunate history would remain intact with Real Sociedad going up by two goals on Sunday night, reports Efe news agency.

Barca -- undefeated so far this season -- are nine points ahead of Atletico Madrid in the league standings, with Valencia 11 points behind and the defending champions Real Madrid trailing by 19 points.

First, it was William Jose knocking in a header on an assist by Xabi Prieto in the 10th minute, and then it was Juanmi Jimenez's turn in the 33rd minute, when he fired a shot that deflected off Sergi Roberto and was swept in by the out-of-position Marc-Andre ter Stegen for the second goal.

But Barcelona managed to wake up five minutes later, when Paulinho moved forward from midfield and popped Luis Suarez's pass in, thus getting Barca on the board.

It was Suarez who sank in a splendid equaliser five minutes into the second half off a pass by Lionel Messi.

In the 70th minute, it was Suarez again after a header forward pass by Thomas Vermaelen that found him alone and perfectly positioned to drill a shot past goalkeeper Geronimo Rulli in heavy rain to give the visitors a 3-2 lead.

Messi put the icing on the cake with six minutes to go when he scored with a free kick.