Two groups remain completely undecided as the Copa Libertadores heads into its final week of the group stage.
All four clubs in both Group Three and Group Seven could still qualify for the next round of the South American continental competition, with the former separated by just one point, while the latter has a two-point gap between first and fourth.
Bolivar are in prime position in Group Seven as they top the standings with eight points and host bottom club Emelec (six points) on Wednesday.
With two straight wins heading into the final matchday, Bolivar should have plenty of confidence but will also be wary of Emelec, as they lost 2-1 to the Ecuadorians in their opening game of the group stage.
The Bolivian club will welcome Emelec to La Paz having not lost on their home turf in three games in all competitions.
William Ferreira will be the key man for Bolivar having scored twice in his side's past three games, including in a 1-0 victory at Leon in their last Copa Libertadores fixture.
Emelec must win to secure a spot in the next stage, while a draw would be enough for Bolivar.
In the other Group Seven clash, Brazil's Flamengo will host Leon of Mexico with both teams on seven points.
Leon won the reverse fixture in Mexico 2-1 and a draw will be enough for the Liga MX outfit to advance as they sit second ahead of third-placed Flamengo due to a superior goal difference.
Flamengo are flying with four wins in their past four games in all competitions, while Leon have not won in the same period.
In Group Three, Lanus top the standings as one of three clubs on seven points, while O'Higgins are bottom with six.
O'Higgins will host the Argentine leaders in Chile on Tuesday, while Colombia's Deportivo Cali will travel to Paraguay to play Cerro Porteno.
The Paraguayan club sit second due to a superior goal difference over third-placed Cali.
Reigning champions Atletico Mineiro have already clinched a spot in the knockout stages in Group Four and will welcome second-placed Zamora to Brazil on Thursday with the Venezuelans needing a win to be certain of advancing.
Santa Fe will play Nacional Asuncion in the other Group Four match with both teams knowing a victory could see them leapfrog Zamora.
In Group One, The Strongest will have to win at home against second-placed Atletico Paranaense to earn a berth in the next round, while leaders Velez Sarsfield will take on winless Universitario.
San Lorenzo face Botafogo, Independiente del Valle will travel to Union Espanola, Cruzeiro will host Real Garcilaso and Defensor Sporting line-up against Universidad de Chile.
In other fixtures, Penarol will take on Deportivo Anzoategui, Santos Laguna face a trip to Arsenal, Newell's Old Boys play Atletico Nacional and Gremio meet Nacional.