Benfica failed to unseat FC Porto atop the Portuguese Liga this season, but the club did lock up second place on Saturday with a 1-0 home win against Uniao Leiria.
Bruno Cesar scored the only goal in the 21st minute, keeping Benfica four points clear of third-place Braga with one game to play.
Braga was hoping Benfica would drop points after a 1-0 win of its own over Beira Mar, but the club must settle for third place after a second-half goal from Custodio.
Champions FC Porto claimed a 2-0 home win over Sporting Lisbon in a match that saw Sporting have two players sent off before Hulk netted a pair of goals in the last 10 minutes for the hosts.
Academica topped Setubal 1-0 on a goal from Edinho before Bruno Gallo was sent off late on for Setubal, while Nacional came from a goal down to tally three times without reply in a 3-1 win over Gil Vicente.
Second-from-the-bottom Feirense took a lead after three minutes against Guimaraes but conceded three goals in the final 50 minutes to lose, 3-1, Maritimo and Olhanense played to a 0-0 draw, and Rio Ave snatched a 2-2 draw at Pacos Ferreira as Joao Tomas scored the equalizer in the 90th minute despite Rio Ave having gone down a man a few minutes earlier.