At the Emirates Stadium, Brazilian striker Jesus finally found the back of the net on home turf for the first time in 2024.
Arsenal failed to take advantage of Liverpool's rare stumble as the Gunners were kept at bay on a frustrating afternoon at the Emirates Stadium.
Expertly taken goals from Nicolas Jackson, captain Enzo Fernandez and Cole Palmer earned Chelsea a 3-0 home win over Aston Villa on Sunday, lifting them to joint second in the Premier League table.
Enzo Maresca does not believe his Chelsea side are in the Premier League title race despite an impressive start to the season in his first campaign at Stamford Bridge.
Arteta had demanded a dynamic display from his team ahead of their trip to the Jose Alvalade stadium and they responded in style.
Mikel Arteta's Gunners remained provisionally third in the standings on 18 points, with the two teams above them -- Manchester City and Liverpool -- playing later on Saturday. Newcastle climbed to eighth on 15 points.
Bukayo Saka became the youngest Arsenal player to score 50 Premier League goals when he returned from a hamstring injury in Sunday's 2-2 draw with Liverpool, but the winger was disappointed to drop two points after being on the verge of a crucial win.
Arsenal bounced back from their embarrassment at Bournemouth as an own goal from Shakhtar Donetsk keeper Dmytro Riznyk gave the Gunners a 1-0 win in the Champions League on Tuesday.
Saturday's 2-0 loss at Bournemouth brought Arsenal's unbeaten start to the league season to a shuddering halt.
Porto manager Sergio Conceicao said Arsenal boss Mikel Arteta insulted his family during the London club's penalty shootout win over the Portuguese side in their Champions League last-16 tie on Tuesday.
"A magic night. We expected a really tough opponent. It's very difficult to generate momentum and that's credit to (Porto)," Arteta told reporters.
The Premier League's top three are separated by a single point with 10 games remaining as a thrilling battle between Arsenal, Liverpool and Manchester City looks set to go to the wire.
The Gunners are aiming to win a first league title in 20 years.
Liverpool captain Virgil van Dijk said a 1-1 draw against Manchester City, that left three sides separated by just one point at the top of the Premier League, was "bittersweet" for the depleted Reds.
Mikel Arteta's side were just minutes away from a damaging draw after Gunners keeper Ramsdale gifted an equaliser to Yoane Wissa.
Martin Odegaard, Jayden Bogle's own goal, Gabriel Martinelli, Kai Havertz and Declan Rice put the visitors 5-0 at half-time before Ben White rounded off the scoring.
Arsenal's free-scoring Premier League form continued as Newcastle were blown away 4-1 at the Emirates on Saturday to move back within two points of leaders Liverpool.
Appearing in a first knockout match in Europe's premier club competition for seven years, Arsenal struggled to break down an organised Porto defence before Galeno's stroke of brilliance in the 94th minute.
The Gunners have not reached the last 16 of the Champions League for seven years and last made it to the quarter-finals back in 2010.
