Messi adds to record as Barca win
Having broken German great Gerd Mueller's 40-year-old record for most goals in a year on Sunday, Messi added to his tally in the 11th minute by tapping into an empty net from David Villa's pass.
Pedro Rodriguez controlled the ball in midfield and delivered a perfectly weighted long pass to the flank for Villa to cross. As goalkeeper Mikel Saizar fell to the ground, Messi tapped the ball in off the underside of the crossbar.
Messi received a cross from Alexis Sanchez to beat Saizar and score his 21st double of 2012 in the 74th. The Argentina forward has now scored two goals in each of the last seven matches he has started.
The 20,000 fans who filled Cordoba's Municipal del Arcangel stadium cheered Messi as he came on the field.
Cordoba began by launching aggressive runs deep into Barcelona's half, and goalkeeper Jose Manuel Pinto was forced to leap athletically to tip out a powerful shot by Lopez Garai in the fifth minute.
Cordoba's Alberto Aguilar forced a save from Pinto when he jumped high to head the ball toward goal in the 43rd.
Messi found Villa with a well-timed pass in the 53rd minute but, having beaten the offside trap, the Spain striker shot over the bar. A powerfully struck shot by Pedro was saved by Saizar three minutes later.
Also in the last 16, Sevilla trounced Mallorca 5-0 with Alvaro Negredo scoring twice. He rose to head in his first from a corner in the 13th, and hit his second beyond goalkeeper Dadu Aouate five minutes later.
Jesus Navas ran up the left flank, crossed a low pass to Gary Medel, who beat defender Pedro Geromel to score Sevillas' third in the 26th.
Sevilla defender Alberto Botia connected with a bouncing free kick to score the fourth in the 48th, before Antonio Luna found the net from an assist by Navas in the 85th.