The forward hit twice to kick off a series of friendlies before London 2012, although the Danes will be pleased at how they rallied in the second 45 minutes
The striker struck twice in the first half as the Selecao looked to be cruising to victory, Niki Zimling's own goal putting the Danes 3-0 down at the break. Morten Olsen's team lifted themselves for the second 45 minutes, however, and found the net through Nicklas Bendtner to give the scoreline a more respectable appearance.
A young Brazil team containing the bulk of the expected squad for the Olympics started on the front foot in Hamburg, looking to push forward at every opportunity through the creative talents of Oscar and Lucas Moura. The Danes were lacklustre at the start, and were punished after just eight minutes when they went a goal down.
Slick play from the Sao Paulo and Internacional youngsters opened up the game for Hulk, and the striker released a wicked dipping effort that caught Thomas Sorensen off guard and flew into the net.
Oscar was also at the heart of Brazil's second five minutes later; carving open the defence with a mazy run, the 20-year-old looked for Hulk in the middle but his cross instead found Niki Zimling, who put past his own keeper.
Sorensen and Lasse Schone were retired by Morten Olsen in favour of Stephan Andersen and Thomas Kahlenberg, and the latter helped the Danish side regroup and start to pose more of a threat having been completely outplayed for the first 25 minutes. Botafogo keeper Jefferson did well to cover an awkward free kick, and followed it up with an accomplished save from Simon Eriksen although the offside flag had already been raised.
Brazil's rhythm had dropped after their frenetic opening, but they demonstrated in the final minutes of the half that they would not forgive any inattention from their rivals. Daniel Agger dallied in possession and was robbed by Oscar, and the ball fell to Hulk who expertly rounded the last defender before firing low past Andersen for his second and his team's third.
The deficit could have been even higher, but Leandro Damiao was flagged for offside after smashing home as the first half finished with Mano Menezes' men in complete control.
Denmark should have cut the deficit in the opening seconds after the break. Brilliant play around the box released Simon Wass, and while Brazil's defence pleaded for offside the full-back crossed for Daniel Agger who inexplicably sliced wide with the goal at his mercy.
The Selecao were also looking dangerous, and Damiao squandered an excellent chance when he failed to control Marcelo's cross following a storming run down the left from the Real Madrid star.
Olsen's men looked far better in the second period, concentrating their attacks down the right where Wass and substitute Dennis Rommedahl exploited the gaps behind Marcelo. Rommedahl gave Brazil a scare on the hour mark, when his shot forced Jefferson to parry for a corner in order to preserve the three-goal advantage. The Brondby veteran then struck the crossbar, firing the ball in from the right while the keeper looked on.
Danish pressure was growing, and with 20 minutes to play they finally managed to hit the net. A wonderful run by Zimling opened the defence up as the midfielder left two men in his wake, and Nicklas Bendtner was left with a simple close-range finish to put the Danes on the scoresheet, although replays showed that the Arsenal man tapped in from an offside position.
An inexperienced Brazil back line continued to struggle against a Denmark side virtually unrecognisable from that which showed so little in the first half, but Mano's men held on to record a seventh consecutive victory and start their pre-Olympic preparations on a positive note.
Denmark will hope for a more positive result next Saturday in front of their own fans, as Euro 2012 preparations continue against Australia. Brazil, meanwhile, move on to face United States in midweek, followed by Mexico before a mouthwatering South American derby against Argentina on June 9.