Despite a number of long-range half-chances from Porto and some quick breaks in the second half by Milan, the one moment of true class at the Stade Louis II came after only 10 minutes when Ukrainian striker Shevchenko scored with a powerful header which gave Porto goalkeeper Vitor Baia no chance.
Shevchenko, voted man of the match afterwards, moved perfectly into place between two Porto defenders to convert a cross from the right from Milan's Portuguese attacker Rui Costa.
With Milan dominating much of the opening half it seemed that more goals would soon come, but, after another well-worked move, again involving Rui Costa and ending with Filippo Inzaghi shooting into the side netting, the game began to get mired in midfield.
Porto's Deco and Derlei were well-marshalled by Milan's Gennaro Gattuso, Clarence Seedorf and, when danger threatened, the peerless Paolo Maldini in defence.
The Portuguese champions failed to make any attacking impression until late in the first half when a speculative shot from Maniche went over the Milan bar.
As the Portuguese league season has already started, Porto should have looked sharper and brighter than Milan, who came into the match having lost six successive pre-season warm-ups.
Too many of Porto's forward moves broke down through poor passing, however, and Benni McCarthy, their new South African signing from Celta Vigo had an ineffective match in attack and was replaced by Edgaras Jankauskas after an hour.
The Lithuanian did not fare much better himself and missed the ball when he had a great chance to equalise just five minutes after coming on in an attempt to liven up the Porto attack.
NEAR MISSES
Porto went close to scoring at the start of the second half with what would have been a quirky goal from Maniche, who floated a shot with the outside of his right foot on to the top of the Milan bar after 47 minutes.
He went close again after 56 minutes with a long-range effort that just went wide. Substitute Jose Boswinga then fluffed a good opportunity late in the game when he shot straight at Milan goalkeeper Dida from six metres.
But for the most part Milan, who won the Champions League last season scoring only four goals in five matches in the knockout stage of the competition and only one in the semi-finals and final, did what they do best.
They held Porto at bay in midfield -- but could not capitalise on some quick breakaway chances set up by Gattuso and Andrea Pirlo, who both had impressive games.
In a rare second-half attack that almost led to a goal, Milan had a chance to double their lead after 74 minutes but Inzaghi was foiled when Baia came off his line to block the shot. Earlier, an Inzaghi header bounced off the Porto bar.
Rui Costa forced Baia into making an excellent save late in the game after dancing through the Porto defence, and Rivaldo added some pep to the Milan attack when he came on for the closing stages.
In the end, though, Milan just about deserved to lift the Super Cup for the first time since 1995 while Porto rarely looked like winning their fifth trophy of the calendar year.
