ASUNCION, Feb. 21 (Xinhua) -- A second-half goal from veteran Paraguay international striker Oscar Cardozo gave hosts Libertad a 1-0 lead in their Copa Libertadores qualifying playoff against Colombia's Atletico Nacional on Thursday.

Cardozo, 35, poked a low shot beyond the reach of goalkeeper Jose Cuadrado after Paulo da Silva headed on a Blas Caceres free-kick at Libertad's Estadio Nicolas Leoz in Paraguay's capital.

The second leg will be played at Nacional's Atanasio Girardot stadium in the Colombian city of Medellin next Thursday. The winner on aggregate will advance to the competition's group stage, which begins March 5.

A scoring draw in the return fixture would be enough to see Libertad through on the away goals rule.

Atletico Nacional won the Copa Libertadores in 1989 and 2016. Libertad have never triumphed in South America's premier club competition.