In the first round of the Champions League league phase, Manchester City defeated Porto 2-0 away from home. After the match, The Athletic analyzed the main talking points from City's performance.

The report stated that Erling Haaland played a decisive role in Portugal, with his two goals helping Manchester City beat Porto 2-0. It was also Enzo Maresca's first Champions League match since taking over as head coach.
In the noisy atmosphere of the rain-soaked Estadio do Dragao, Manchester City took control from the start and dominated possession, although Porto's defense prevented them from creating clear scoring chances early on.
However, Maresca's team grew in confidence, and only the excellent performance of goalkeeper Diogo Costa, who made two superb saves to deny Haaland, kept them from scoring.
Before halftime, the match was stopped for a long period because Guehi needed treatment after his arm struck an opponent's head. Despite protests from the hosts, Manchester City defender Guehi was not punished.
Haaland finally broke through Porto's defense in the second half. Phil Foden kept the ball from going out of play with great effort and then passed to Enzo Fernandez, who found Haaland inside the box. The Norwegian striker rose high and, although he could not generate much power on the shot, cleverly guided the ball inside the far post.
The match was open and entertaining, and Porto also had chances to equalize. Their penalty was ruled out because of an earlier offside; William Gomes nearly scored after pressing Donnarumma; Pepe found himself unmarked at the far post but sent his volley wide.
But Haaland had the final say. Substitute Ait-Nouri provided the pass, and Haaland finished low before the end of the match. It was his 59th goal in 59 Champions League appearances.
The closing stages became chaotic, with Haaland receiving a yellow card after a confrontation with Pablo Rosario, who was also booked. Costa made another excellent save to deny Enzo Fernandez.
How did Manchester City get the best out of Haaland?
After Manchester City's 1-0 win over Coventry at the weekend, Maresca clearly told debutant Iliman Ndiaye that he wanted the winger to stay high and remain wide. "He drops too deep, and that is not what we want. That space is more for Gvardiol; we need him to position himself further forward."
In this match, Semenyo started as the left winger. The 26-year-old was sometimes too aggressive in his movements and made too many mistakes in possession, but he followed the coach's instructions well by staying on the flank, pulling defenders outward and creating space for teammates' runs. The passing network showed that Semenyo often stayed alone on the left, with Enzo Fernandez or Gvardiol providing support when they moved forward.
When this situation occurred, Semenyo gained space to cut inside and delivered curling crosses with his right foot. This repeatedly created opportunities for Haaland, with aerial balls constantly aimed at the tall striker, who eventually broke the deadlock with a trademark long-range headed lob.
The goal came from Rayan Cherki's overlapping run. City's best chance of the first half came when Foden drove forward at high speed through the inside channel, received Semenyo's pass and crossed for a teammate at the far post.
Haaland scored his second goal by sending a right-footed shot into the bottom corner. Before that, he had already scored three consecutive headed goals. This was not accidental; this type of wide combination and movement pattern is a routine repeatedly practiced in Maresca's tactical playbook.
Should Marc Guehi have been sent off?
Manchester City firmly controlled possession and territory in the first half and largely suppressed Porto, but tension was building. Porto right winger Gomes pressed aggressively whenever Gvardiol had the ball, and their continued battles led to Gvardiol receiving a yellow card. A confrontation also broke out in the players' tunnel at halftime.
Before halftime, Marc Guehi collided with Vega, further intensifying the emotions between the teams. Guehi attempted a headed clearance and collided with the opposing midfielder while sprinting at speed. The incident happened quickly: Guehi charged toward the ball, extended his right arm for leverage and struck the opponent in the face, leaving Vega with bruising around the eye.
The referee chose a lenient punishment, judging that Guehi raised his arm only to gain leverage for his jump. In slow motion, the action looked worse and appeared almost intentional, with his elbow widely away from his body during the jump; however, from the live angle it could only be judged as an unfortunate accident. This of course did not reduce the injured player's pain.
Apart from that reckless collision, Guehi was arguably Manchester City's most composed defender on the night, making several key clearances and progressing the ball effectively.
How was Ayoub Bouaddi's first start?
Ayoub Bouaddi was replaced by Kovacic in the 75th minute, but the substitution was not because of poor performance. The 18-year-old Morocco international made his first start for Manchester City's first team and impressed throughout.
While adapting to Manchester City's system and the pace of the Premier League, European competition may suit him better. For such a young player to handle the ball calmly at this level is impressive in itself. In a hard-fought City victory, Bouaddi contributed throughout the match in both attack and defense: he kept possession under high pressure, found teammates and stepped forward to disrupt opposition attacks.
His teammates clearly trusted him to receive the ball in tight spaces. Cherki in particular was willing to give him difficult passes, believing he could bring the ball out safely. City signed him because of his huge potential, but the youngster can already provide immediate and consistent contributions. Maresca replaced several players who were struggling, and Bouaddi was clearly not among them.
Why did Maresca replace Cherki and Semenyo?
Maresca made decisive substitutions at Estadio do Dragao. Gvardiol looked unsettled early on, and after briefly stabilizing and stopping several dangerous Porto attacks, he began losing possession frequently and received a yellow card for delaying play and an unnecessary foul.
Before halftime, home fans wanted him to receive another yellow card and be sent off. Although the foul was not enough for a second booking, having already been cautioned made his later substitution unsurprising. The change came after the goal in the 47th minute rather than at halftime.
This suggested another issue, but when the match became tighter midway through the second half, Maresca did not become complacent. He replaced Cherki, who started losing the ball when City had opportunities to score a second goal, and Semenyo, whose poor touches often interrupted attacks.
Elliot Anderson and Ndiaye helped Manchester City stabilize the game. Bouaddi and Foden were substituted with 15 minutes remaining. Their performances before that had been much better, which may suggest they were tired or that Maresca wanted to bring on fresher players.
After Manchester City's ultimately impressive transfer window, they were able to make such choices.