Lanus had led after just seven minutes on Thursday and dominated the match in Argentina, but Ferreira's thunderous shot in second-half stoppage time saw Bolivar score a vital away goal and head back to Bolivia with plenty of hope they can qualify for the semi-finals.
Ferreira collected the ball in the 91st minute and Bolivar's captain unleashed his shot from further than 30 yards, and the ball went in inside the far post, despite Lanus goalkeeper Agustin Marchesin getting both hands to it.
Oscar Benitez scored Lanus' goal, getting on the end of a sharp passing move at the top of Bolivar's penalty area and thrashing his shot into the top corner.
Lanus looked deflated after the final whistle having had 66 per cent possession and 10 shots to the visitors' six, but failing to clinch victory.
Coach Guillermo Barros Schelotto will have to lift his players quickly, as Lanus must travel to Bolivar next week for the second leg on May 15.
In the other quarter-final first leg on Thursday, Defensor Sporting struck twice in the last 15 minutes to win 2-0 at Atletico Nacional.
Two attacks down the left saw Defensor score their goals with Adrian Luna claiming an assist on both.
Luna's first-time cross picked out Leonardo Pais at the back post in the 77th minute to give the Uruguayan visitors the lead in Colombia.
A counter-attack six minutes later saw Defensor claim a 2-0 lead with Luna teeing up fellow substitute Nicolas Olivera.
Despite slipping over as he received Luna's pass, Olivera managed to keep the ball under a challenge from a Nacional defender and then slotted his shot past Franco Armani.
To add to the home side's woes, Nacional had Edwin Cardona sent off with four minutes remaining.
