RIO DE JANEIRO, March 22 - Midfielder Juan Roman Riquelme scored his first goal since re-joining Boca Juniors on Thursday, helping his side to a 3-0 win over Toluca in the Libertadores Cup.

Ze Roberto's stoppage-time winner gave Santos a 2-1 win at Gimnasia-La Plata, who had equalised one minute earlier, and sent the Brazilians into the last 16. Paraguayan champions Libertad beat El Nacional 1-0 to stay unbeaten.

Boca's win in Buenos Aires took the five-times champions back to the top of Group Seven as they avenged last week's 2-0 defeat by their Mexican opponents.

Boca have seven points from four games, one ahead of Toluca and three clear of Bolivar.

Antonio Naelson hit the crossbar for Toluca in the first minute before Boca took control.

Riquelme set up the first goal in the 16th minute when he floated over a free kick which was headed in at the near post by defender Jonatan Maidana.

Riquelme, who returned for a second stint at Boca on loan from Villarreal after falling out of favour at the Spanish club, tapped in the second eight minutes later after Martin Palermo pulled the ball back.

Toluca's problems continued when Jose Manuel Cruzalta was sent off for a second bookable offence four minutes before halftime.

Cruzalta's first booking was for an ugly foul on Palermo that led to the free kick from which Boca opened the scoring.

Riquelme was also involved in the third goal in the 83rd minute, playing a one-two with substitute Mauro Boselli who cleverly lobbed the ball over Hernan Cristante from the edge of the area.

PENALTY MISS

Santos made it four wins out of four in Group Eight after beating their Argentine opponents with goals at the start and end of the game in La Plata.

Marcos Aurelio volleyed home in the third minute after the Gimnasia defence failed to cut out Rodrigo Tiui's low cross.

Santos appeared to throw the game away as Cleber Santana missed a 34th minute penalty and Tiui headed wide with the goal at his mercy in the 88th minute.

Sergio Leal headed Gimnasia level one minute later but Santos had the last word when Kleber's throw-in was flicked into the path of Ze Roberto and the former Bayern Munich player rifled the ball into the roof the net.

The win guaranteed Vanderlei Luxemburgo's team a top-two finish with two matches to spare. Defensor Sporting have six points and Gimnasia three.

Paraguay international Carlos Bonet scored in the 10th minute as Libertad beat Ecuadorean army club El Nacional 1-0 in Asuncion. Libertad top Group One with 10 points from four games, four ahead of America and Banfield.

Despite having a strong side including several Ecuador internationals, El Nacional have just one point.