Tigre, who are challenging for the title and fighting relegation at the same time, drew at 1-1 Atletico Rafaela and troubled San Lorenzo boosted their survival hopes by coming from two goals behind to beat Newell's Old Boys 3-2.
Riquelme set Boca on their way when he floated over a free-kick which defender Juan Insaurralde met with a near post header to open the scoring after 13 minutes.
Three minutes before half-time, the mercurial playmaker got away from his marker at the far post, collected Clemente Rodriguez's long cross and laid the ball into the path of Dario Cvitanich to score into an empty net.
San Lorenzo, meanwhile, climbed to 18th, putting them in the play-off zone, with their spectacular win over Newell's Old Boys, who dropped four points behind Boca in the Clausura.
Newell's raced to a 2-0 lead in half an hour as Pablo Perez scored with a long-range effort and Fabian Munoz pounced after the hosts gave the ball away in defence.
