SAO PAULO: Colombia secured their place in the knockout stages of the men’s Olympic football tournament after a surprisingly convincing 2-0 win over Group B winners Nigeria in the Arena Corinthians.

A first-half strike from captain Teofilo Gutierrez and a second-half penalty from Dorlan Pabon ensured the South Americans joined their West African opponents in the quarter-finals.

Needing a win to secure their place in the last eight, Los Cafeteros took a fourth-minute lead through Sporting Lisbon’s Gutierrez who volleyed a through pass from Pabon beyond Nigeria goalkeeper Daniel Akpeyi.

That goal gave Colombia the confidence to create more quality chances. In the 19th minute, Akpeyi denied Harold Preciado’s close-range header before Pabon shot wide.

Nigeria created chances of their own before the break with Oghenekaro Etebo putting Sadiq Umar’s low cross wide of a and then testing Cristian Bonilla with a well-struck free-kick which ricocheted away off the legs of the Colombia goalkeeper.

Colombia’s determination to reach the knockout stages was reflected in their willingness to extend their lead after half-time.

Just after the hour they were rewarded from the penalty spot through Pabon after Akpeyi brought down Preciado.

Colombia thus finished second in Group B with five points, one behind group winners Nigeria. Colombia now play Brazil in their quarter-final clash in Sao Paulo while Nigeria travel to Salvador to play Denmark.

The other Group B game saw a pyrrhic 1-0 win in Salvador for Japan over Sweden both of whom duly went home. Japan signed off with a victory courtesy of a second-half strike by Shinya Yajima on an assist by Ryota Oshima.