Benfica won the Portuguese Primeira Liga for a record-extending 38th time by beating Santa Clara 3-0 on Saturday, four years after they last lifted the trophy.
Last season's champions Porto finished second after they also beat Vitoria Guimaraes 3-0, but they needed Benfica to lose to have a chance of retaining the title on the final day.
Goncalo Ramos, Rafa Silva and Alejandro Grimaldo struck for the hosts at the Estadio da Luz in Lisbon, as Roger Schmidt's side saw off bottom-of-the-table Santa Clara with ease.
Benfica, who blew a chance to lift the title last weekend by drawing with Sporting Lisbon, made no mistake this time.
Only a defeat would have foiled their title challenge and Ramos headed home from inside the six-yard box after seven minutes to put his side on the right track.
Despite selling midfielder Enzo Fernandez to Chelsea in January after his triumphant World Cup campaign with Argentina, Benfica have had a strong campaign and also reached the Champions League quarter-finals.
Silva hit the second for Benfica at the end of a razor-sharp break, exchanging passes with Joao Mario and then firing home with the aid of a deflection.
Former Barcelona defender Grimaldo netted the third from the penalty spot after an hour and produced an emotional celebration, in his last game for the club before he joins Bayer Leverkusen.
Porto did their job at home against Guimaraes with goals from Mehdi Taremi, Otavio and Evanilson, but ultimately fell short, finishing two points behind the new champions.