Swedish striker Henrik Larsson grabbed an early lead for the visitors and Samuel Eto'o stretched the lead after the break.
The Catalans are now 12 points clear at the top of the standings as their arch-rivals Real Madrid, who will play Real Betis on Sunday, come second on 52 points.
Larsson, recently on fire, didn't waste much time as he controlled Ronaldinho's inch-perfect volley and drilled a finish home in the seventh minute.
Six minutes after re-start, Dutch international Mark Van Bommel slammed a powerful shot against the post but Eto'o poked home on the rebound to take his season's scoring tally to 20 goals.
In another match, Xisco headed home midway thorough the second-half to help Deportivo Coruna beat Getafe 2-1.
Victor fired Deportivo into the lead on the half-hour mark but Getafe leveled through Sergio Pachon in the 58th minute.
Deportivo are now eight with 43 points, leading Getafe, who are two places down, on six points.