Benfica won the Portuguese Primeira Liga for the 38th time, beating Santa Clara 3-0 on Saturday, four years after they last won the trophy.
Last season’s champions Porto finished second after beating Vitoria Guimaraes 3-0 but needed a Benfica defeat to have any chance of retaining the title on the final day.
Goncalo Ramos, Rafa Silva and Alejandro Grimaldo scored for the hosts at Estadio da Luz in Lisbon as Roger Schmidt’s side easily cleared Santa Clara from bottom of the table.
Benfica, who squandered their chance to win the title last weekend by drawing with Sporting Lisbon, did not make a mistake this time.
Only a defeat would thwart their title challenge, and Ramos came home from the penalty area after seven minutes to put his side on the right track.
Despite the sale of midfielder Enzo Fernandez to Chelsea in January following his World Cup triumph with Argentina, Benfica had a strong season and reached the quarter-finals of the Champions League.
Silva scored Benfica’s second goal at the end of a razor-sharp break, trading passes with Joao Mario before scoring home with the help of a rebound.
Former Barcelona defender Grimaldo scored his third from the penalty spot after an hour and sparked an emotional celebration in his last game for the club before joining Bayer Leverkusen.
Porto did its home job against Guimaraes with goals from Mehdi Taremi, Otavio and Evanilson, but ultimately lost, finishing two points behind the new champions.