Lucas Paquetá scored Brazil’s only goal in the 72nd minute in a 1-0 win over Colombia, putting the Seleção 18 points ahead of fourth-place Chile, which can add only 15 points from its five remaining matches.
Sixth-place Uruguay can still total Brazil’s 34 points, but it will face Chile in the last round of qualifying, which makes it mathematically impossible for both of them to overtake the leader.
Also on Thursday, third-place Ecuador beat last-place Venezuela 1-0 with a goal by Piero Hincapié and Chile had a key 1-0 victory at Paraguay thanks to an own goal by Antony Silva after a corner kick.
Peru and Bolivia will face off later Thursday. Uruguay will host Argentina on Friday.
Brazil has 11 wins in 12 matches — its match with second-place Argentina in September was bizarrely suspended after seven minutes of play because of concerns from authorities over breaches of COVID-19 protocols. FIFA has not yet decided whether it will be replayed.
Ecuador (20 points) follows its two major rivals in South American qualifiers, with Chile, Colombia and Uruguay tied with 16 points. The Chileans skip ahead for now on goal difference.
The fifth-place team in South American qualifiers goes into an intercontinental playoff for a spot in Qatar.