As the Benfica manager came at St James' Park and praised Newcastle's coach and his players, local supporters feared a tough match. However those worries vanished thanks to a strike from Anthony Gordon and two more from substitute the forward, ensuring Benfica's new manager would not cause any trouble for Newcastle.
Mourinho had predicted that Newcastle would be very physical, but his own team showed their similar aggressive approach. The visitors clearly delighted in breaking up Newcastle's early efforts to establish a smooth passing tempo.
Adding to Newcastle's issues, key midfielders, Tonali and Joelinton, began as substitutes as they continued recovering from illness and a knock respectively.
Before kick-off, the coaches shared a perfunctory, reserved greeting, and it soon became clear that the Benfica coach had instructed his team to quiet the home fans by delaying the game and lowering the temperature at every chance.
The visitors' strategy yielded varied outcomes, but when Gordon and his teammates succeeded to break through Benfica's backline, they at first found it hard to create clear chances.
Additionally, the Belgium winger Dodi Lukebakio almost showed scoring skill when, after beating the defender on the ground, he tested Nick Pope with a powerful strike that got an excellent single-hand stop. No wonder the goalkeeper still hopes for an national team recall in time for the World Cup.
But when Lukebakio directed a further attempt against the woodwork, Newcastle roused themselves. Jacob Murphy shot off target, and Benfica's keeper made an excellent close-range stop from Bruno Guimaraes before Anthony Gordon at last broke the scoreless tie.
The England winger's scorching speed had created problems for Mourinho all night, and he calmly slotted the opener past the goalkeeper after his teammate's quick ball into the area paid off.
When Newcastle's intense, pressing game was not second-guessed by Benfica, Jacob Murphy, preferred over £55m Anthony Elanga, was available to pass a ground cross across the goal for Gordon to finish.
Right from the start, the Portuguese team could not be accused of defending deeply and playing for a draw, but now their players pushed forward with total abandon. The winger repeatedly displayed an skill to unsettle Howe's back four, and the Magpies were probably relieved to reset at the break.
The first half concluded with Pope again saving his side by tipping the attacker's left-foot wide of the goal frame, and as the sides emerged for the second half, the match seemed finely balanced.
While Anthony Gordon, clearly buoyed by netting his fourth goal in three European games this campaign, played with the zeal of a winger aiming to shift the balance in his team's favor, Lukebakio had different plans.
Mourinho's winger had previously emphasized that, while Burn is a fine centre-back, he is not a born full-back, and home fans were nervous every time Lukebakio moved forward.
The Newcastle manager might have felt easier had Lewis Miley, deputising for Sandro Tonali, not directed a set-piece over the crossbar from a well-placed position. Instead, this absorbing game continued to move from one goal to the other, prompting the manager to introduce Joelinton and Barnes in place of Ramsey and Jacob Murphy.
The Benfica boss, meanwhile, brought on an extra striker in Ivanovic. It would arguably prove a gamble that backfired.
Before that, Benfica, and in particular their Portugal back Silva, had performed a good job in limiting Woltemade's room and pushing the German centre-forward deep. However, with defender Dedic off, the backline was underpowered, and the path was clear for Barnes to show that Anthony Gordon is not Howe's only goal-scoring wide player.
The home side's double substitution was already paying off by the time Pope sent a wonderful long throw in Barnes's path. When Silva, on this occasion, misjudged the bounce, the winger was clear, accelerating into the penalty box before maintaining commendable composure to fire a sublime strike past Trubin.
After Harvey Barnes slid a low effort through unfortunate Trubin's feet after receiving Gordon's stellar through ball, it was all over. The Benfica manager had cautioned that the Magpies have four very fast wide attackers, and three goals from a pair of wide men had shattered his chances of securing the team's first Champions League result of the campaign.
A passionate urban explorer and travel writer, sharing city adventures and cultural discoveries from around the world.