The draw for the Copa Libertadores round of 16 took place in Paraguay on Monday.
Wednesday's results left all three teams on 10 points but Flamengo (+6) and LDU Quito (+4) pipped Penarol (+2) on goal difference.
Palmeiras reached the knockout phase thanks to a 4-0 rout of Melgar, while San Lorenzo also progressed despite their 1-0 loss to Junior.
Paolo Guerrero hits a double to sink Palestino 3-2 as Brazilian side Internacional seal their place in the last 16 of the Copa Libertadores.
Marco Ruben led Athletico Paranaense to an impressive win over Boca Juniors in the Copa Libertadores.
Playing behind closed doors at the Monumental, River Plate were held by Palestino in the Copa Libertadores.
Last season's runners-up Boca Juniors were held by Bolivian hosts Jorge Wilstermann in Group G on Tuesday.
We assess the leading candidates for glory and the potential stars ahead of the start of the 2019 Copa Libertadores.
River Plate and Lanus reached the Copa Libertadores semi-finals after overturning first-leg deficits.
San Lorenzo accounted for Lanus 2-0 in Wednesday's all-Argentinean clash thanks to a brace from Nicolas Blandi.