Hernan Barcos' second-half brace helped in-form Gremio to a 2-0 win at Botafogo at the iconic Maracana on Sunday.
Gremio are unbeaten in nine league matches, while they have not conceded a goal in eight outings to sit fifth in the standings with 43 points after 25 rounds.
Former Brazil coach Scolari took over from Enderson Moreira in July, with Gremio languishing in 10th position having collected 19 points from 12 games.
But Scolari, who oversaw Brazil's humiliating 7-1 defeat to Germany at the 2014 World Cup, has steered Gremio into championship contention.
And the dual top-flight champions maintained their charge up the standings thanks to Barcos after a goalless opening half.
The veteran Argentinean striker Barcos opened the scoring five minutes into the second half, tapping into an open net after 40-year-old Ze Roberto played the ball across the six-yard box.
Barcos, 30, was at it again with 13 minutes remaining, composing himself before placing the ball beyond Botafogo goalkeeper Marcelo Grohe from close range.
Gremio are 10 points adrift of league leaders and defending champions Cruzeiro, who were held to a scoreless draw by Sport Recife on Saturday.
Scolari's men, however, are level on points with Sao Paulo and Atletico Mineiro.
Sao Paulo's poor form continued after they crashed to a third defeat in four games, losing 3-1 at home to Fluminense.
Hosts Sao Paulo were on level terms just shy of the hour-mark thanks to Alexandre Pato, who cancelled out Fred's 53rd-minute opener.
But Fluminense - sixth in the standings - powered past Sao Paulo in the final stages, with Wagner putting the visitors ahead in the 73rd minute before Dario Conca sealed the points late on.
Mineiro were also triumphant, accounting for third-bottom Vitoria 2-0.
Internacional are four points clear in second place thanks to their 4-2 victory over basement side Coritiba.
Eduardo Sasha's brace set the tone for Internacional, while Andres D'Alessandro and Alex were also on target for Abel Braga's men before the match was suspended for 16 minutes due to issues with the floodlights.
In other results, Atletico PR were 1-0 winners as Corinthians slumped to back-to-back defeats.
Santos downed Goias 2-0, while Flamengo lost 2-1 at Bahia.
Cleitinho scored two goals in as many minutes to help Figueirense overcome 10-man Palmeiras 3-1.
Chapecoense and Criciuma played out a 1-1 draw.
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