Defending champions Atletico Mineiro saw their perfect start to Group 4 come to an end after a 2-2 draw in Paraguay.
Marcos Melgarejo opened the scoring for the hosts in the ninth minute at the Estadio Antonio Aranda, tucking away Fredy Bareiro's through ball.
Ronaldinho set up Josue's 22nd-minute equaliser as the former Barcelona and Milan star used his neat touch to find room before picking out the midfielder to finish in a one-on-one.
Just five minutes later and the Brazilian visitors were ahead as Jesus Datolo's strong run from the left led to Jo tapping in the easiest of goals.
The goal stood despite replays showing the star striker was offside.
But the hosts found an equaliser of their own three minutes before full-time as Silvio Torales drilled a penalty down the middle and just under the crossbar.
Despite the draw, Atletico remain top on seven points, three clear of Nacional Asuncion and four ahead of both Santa Fe and Zamora.
Juan Falcon's 84th-minute goal saw Zamora to a 2-1 win over Santa Fe at the Estadio Rafael Agustin Tovar.
Pedro Ramirez's cheekily under-hit penalty on the hour-mark put Zamora ahead before a sloppy turnover led to Jonathan Copete's equaliser on 72 minutes.
But Falcon turned his marker wonderfully before drilling a finish into the bottom corner to give Zamora the victory.
Independiente del Valle ensured Group 2 remained close with a dramatic 2-1 victory at home to Botafogo.
Christian Nunez drilled in a 26th-minute opener for the hosts before Bolivar levelled just before the hour-mark for Botafogo.
But the visitors were reduced to nine men on 74 minutes when Bolivar and Edilson saw red, and Independiente del Valle capitalised.
Junior Sornoza struck a brilliant 30-yard effort to give the Ecuadorians victory.
Botafogo are top on four points, with Independiente del Valle (four), San Lorenzo (four) and Union Espanola (three) close behind.
San Lorenzo and Union Espanola played out a 1-1 draw.
In Group 7, Flamengo climbed up to second as Everton's brace helped them to a 2-2 draw at home to Bolivar.
