Flamengo, who have failed to recapture their 2009 form and are under their third coach this season, are 14th just five points above the relegation zone after failing to win in their last five matches.
Their Rio arch-rivals Fluminense lost their unbeaten record in a 2-1 away loss to Guarani, however, and now lead the Brazilian championship race by just one point from Corinthians, who crushed Goias 5-1 on Saturday and have a game in hand.
At the halfway stage of the championship, Flu have 38 points from 19 matches, Corinthians 37 while Botafogo, Cruzeiro, Santos and South American champions Internacional are all on 31.
Flamengo, in new coach Silas's first and only match in charge at the Maracana, had more of the ball against a Santos side missing two of their bright young forwards - the injured Paulo Henrique Ganso and suspended Neymar - but failed to translate possession into goals.
TOTAL CLOSURE
Having to leave the Maracana, which is set to undergo a $398-million refurbishment over the next three years, is another blow for the club since the huge crowds Flamengo attract are generally worth home points.
Originally, Rio city planned to leave the Maracana open to half its 90,000 capacity until the end of the season so as not to handicap Flu and Fla.
World Cup organisers, however, sought total closure of the stadium this week to speed up work which starting six months late. The two teams will play home games at grounds outside Rio and at Botafogo's Engenhao.
"It's a situation I'd like to reverse with a piece of magic or something like that," said Silas.
"But it's only in our day-to-day work that we can progress. It's important to understand there are 19 matches (to go) and we can't drop many points," he told reporters.
Flu were stunned by two goals from free kicks by Guarani defenders Baiano and Fabao, one in each half, after taking a 13th-minute lead through Emerson.
Corinthians began Saturday's match with a nasty surprise when Goias opening the scoring after seven minutes through left back Junior.
After Bruno Cesar equalised at the end of the first half, however, Corinthians ran riot in the second with two goals from striker Iarley, one by Jorge Henrique and a Marcao own goal.
