When the Benfica manager arrived at St James' Park and praised Newcastle's coach and his players, local supporters feared a tough match. However those worries vanished due to a goal from Anthony Gordon and a brace from replacement the forward, ensuring the visitors' coach did not inflict pain for Newcastle.
Mourinho had predicted that the home side would be very physical, but his Benfica players displayed their own combative approach. The visitors certainly enjoyed breaking up Newcastle's initial attempts to establish a smooth attacking tempo.
Adding to the home team's challenges, two midfielders, Sandro Tonali and Joelinton, started as substitutes as they continued recovering from sickness and a knock respectively.
Before kick-off, the two managers exchanged a perfunctory, cool greeting, and it quickly became apparent that Mourinho had told his team to subdue the home fans by slowing Newcastle and lowering the intensity at every chance.
The visitors' tactic produced varied results, but when Gordon and the Newcastle attack managed to dismantle the backline, they initially struggled to generate good chances.
Moreover, the Belgium winger Lukebakio nearly showed scoring skill when, after leaving the defender behind, he tested Nick Pope with a tremendous strike that got an excellent one-handed save. It's no surprise Pope retains hope for an national team recall in time for the global tournament.
Yet when the winger directed a further attempt off the woodwork, Newcastle woke up. Jacob Murphy fired wide, and Benfica's keeper made an impressive near-post save from Bruno Guimaraes before Anthony Gordon finally broke the scoreless tie.
Gordon's blazing speed had caused problems for Mourinho all night, and he calmly slotted the opener past Trubin after his teammate's quick cross into the area paid off.
On the occasion Newcastle's intense, high press was not anticipated by Benfica, Murphy, chosen over £55m Anthony Elanga, was available to pass a ground ball across the face of goal for Gordon to polish off.
From the beginning, Benfica could not be accused of defending deeply and seeking a point, but now Mourinho's side attacked with real abandon. Lukebakio repeatedly showed an ability to destabilize Howe's defense, and the home team were likely grateful to regroup at the break.
The opening period ended with Pope once more rescuing his team by diverting Lukebakio's left-foot around the post, and as the sides emerged for the next period, the match seemed finely poised.
If Anthony Gordon, evidently boosted by netting his fourth goal in three Champions League games this season, played with the determination of a wide player aiming to shift the power balance in his team's direction, Lukebakio had other plans.
Mourinho's winger had previously shown that, while Burn is a capable central defender, he is not a born full-back, and Newcastle fans were in mouths every time he advanced.
Howe might have felt easier had Lewis Miley, deputising for Sandro Tonali, not directed a corner over the crossbar from a good spot. Instead, this thrilling game continued to swing from one goal to the other, prompting Newcastle's manager to bring on the midfielder and Barnes in place of Ramsey and Jacob Murphy.
Mourinho, meanwhile, brought on an extra forward in Franjo Ivanovic. This would arguably prove a gamble that backfired.
Before that, Benfica, and especially their Portuguese defender Antonio Silva, had performed a fine job in restricting Woltemade's space and pushing the Germany centre-forward back. But now, with right-back Dedic substituted, the backline was underpowered, and the path was clear for Barnes to prove that Gordon is not Howe's only goal-scoring wide player.
The home side's two changes was already paying off by the time Pope dispatched a wonderful throw in Barnes's path. When Silva, on this occasion, misjudged the bounce, the winger was clear, sprinting into the penalty box before keeping commendable poise to lash a superb shot past the keeper.
After Barnes rolled a shot through poor Trubin's feet after receiving Anthony Gordon's stellar pass, it was finished. Mourinho had warned that the Magpies have four quick wingers, and a trio of strikes from two wide men had destroyed his chances of securing the team's first Champions League result of the campaign.
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