San Martin of Peru defeated River Plate of Argentina 2-0 for the greatest shock of the first round of the Copa Libertadores so far.

San Martin started very strongly, and piled heavy pressure on the River Plate goal, almost straight from the kick off.

They created a number of clear goal scoring opportunities to take the lead, but were kept out by River Plate goalkeeper Juan Pablo Carrizo, who was in good form.

Diego Simeone's side looked extremely vulnerable in the defense, and it just seemed a matter of minutes before the Peruvian outfit would take the lead.

In the 15th minute Roberto Ovelar put San Martin ahead, with a delicate touch that beat a stranded Carrizo in the River goal.

After going behind River seemed to liven up a touch, but lacked any authority in the attack, because their midfielders constantly pumped long balls to lanky striker Sebastian Abreu, who was off touch.

In the second period River Plate controlled proceedings, but San Martin still looked the more dangerous of the two sides, as they constantly broke on swift counterattacks.

River seemed to have been awarded a spot kick, for a foul in the area, but Ariel Ortega received a yellow card for a dive.

The Argentines pressed, and completely played in San Martin's half, and could have equalized through Abreu on a couple of opportunities, but the Uruguayan target man was kept out by an alert Leao Butron in the San Martin goal.

From the run of play, San Martin sealed a 2-0 victory, with an impressive strike from Jose Diaz in second half injury time. Diaz charged through the River defense with incredible skill, and beat Carrizo with a classy finish.