Porto seized their fifth consecutive Super Cup and first trophy under new coach Paulo Fonseca with a commanding performance.
They started all guns blazing, scoring with their first chance through forward Lica, a new signing from Estoril, who smashed a tap-in just five minutes into his debut.
The almost 30,000 fans at the packed Aveiro stadium were treated to a series of flowing attacking plays from Porto that also made the most of some lax defending.
Guimaraes, who had shocked Benfica with a 2-1 win in the final in May, never looked like a threat and were punished with the second goal after 17 minutes when Colombia striker Martinez fired in a textbook header.
Just before the halftime whistle, Argentine captain Gonzalez buried the third with a sweet first-time volley to earn Porto an inspiring start to the season.
The Portuguese Premier League kicks off next weekend.