RIO DE JANEIRO, March 15 (Reuters) - Velez Sarsfield, playing the entire second half with 10 men, fought back from 3-1 down to beat Universitario 4-3 and reach the last 16 in the Libertadores Cup on Tuesday.
Atletico Nacional won 5-1 at Paraguay's Cerro Porteno despite having two players sent off in the second half.
Velez became the first team to make sure of a place in the next round after a stirring comeback in Buenos Aires maintained their 100 per cent record.
The Argentines have 12 points from four games in Group Five, enough to guarantee a top-two finish. Universitario are bottom with one point.
Six of the goals came in the first half before Damian Escudero scored the winner with three minutes left.
The Peruvians went ahead after only 40 seconds with a close-range goal from Rafael Maceratesi before Marcelo Bustamante scrambled an equaliser five minutes later.
Gaston Sangoy put Universitario back in front almost immediately and German Centurion made it 3-1 in the 23rd minute with a diving header following a free kick.
Velez then grabbed two goals in three minutes before halftime, Escudero squeezing past three defenders to score in the corner before Mauro Zarate levelled with a free kick.
In between, the 1994 champions had Dario Ocompa sent off for an ugly challenge.
Both teams had chances in the second half before Escudero collected the ball in midfield, ran at the heart of the Universitario defence and scored from the edge of the area.
'It was a miracle that we won,' said Velez coach Miguel Angel Russo. 'We reacted well in adversity.'
There was more drama in Group Seven where Cerro Porteno's unbeaten record went up in smoke in Asuncion.
The Paraguayans, playing in their stadium known as the Pressure Cooker, quickly ran out of gas after a lively start and trailed 4-1 at halftime.
Left back Vladimir Marin finished off a sweeping move with an angled shot in the 17th minute, Sergio Galvan Rey scored from long range in the 25th after poor defending and Victor Aristizabal added a third two minutes later.
Walter Fretes pulled one back from a free kick in the 39th minute but Aristizabal made it 4-1 for the Colombians in the 44th minute after the Cerro defence lost possession.
Despite having Aldo Ramirez and Gerardo Bedoya sent off in an eight-minute spell, Atletico, playing their first game under new coach Carlos Navarete, added a fifth in the 74th minute when Marin finished off a counter-attack.
Atletico, champions in 1989, lead with six points from three games after their first win while Cerro, five times beaten semi-finalists, dropped to third with four.
In Cusco, at 3,400 metres above sea level in the Peruvian Andes, Cienciano won their first game in Group One as they overcame Venezuela's Caracas FC 2-1.
Brazilian Roberto Silva scored a 75th-minute winner after Julio Garcia had given Cienciano an early lead with a looping 30-metre free kick.
Wilson Carpintero equalised for Caracas eight minutes after halftime.
Cienciano moved up to third with three points from three points and Caracas, who have one point, dropped to last. Defending champions Sao Paulo from Brazil lead with six points followed by Mexico's Guadalajara with four.