Argentinian striker Blanco struck with two minutes to go in normal time as Barcelona salvaged a 1-1 draw at home to Emelec in the Third Stage clash, which pits the First Stage and Second Stage winners against each other.
First Stage champions Emelec opened the scoring at the Estadio Monumental Isidro Romero Carbo on Wednesday.
Angel Mena found the net in the 19th minute, giving the 11-time Primera A champions the lead after being played in by team-mate Miller Bolanos, who slid the ball between two Barcelona defenders.
But just as Emelec appeared on track for a priceless 1-0 win on the road, Blanco popped up with a late equaliser for Barcelona, who topped the Second Stage standings by two points ahead of Independiente del Valle.
Blanco, who scored 11 goals in the Second Stage, headed past Emelec goalkeeper Cristian Arana, sparking wild celebrations in Guayaquil.
The return leg will be played at the Estadio George Capwell on Sunday.
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