LONDON -- Manchester City is the team to catch in the Premier League, and it's getting even more challenging.
Pep Guardiola's side moved eight points clear with a 3-1 victory over Arsenal on Sunday when second-place Manchester United lost 1-0 at Chelsea. Tottenham trails United on goal difference and is a point ahead of defending champion Chelsea after beating last-place Crystal Palace 1-0.
There is still more than two-thirds of the season to go but City is looking a formidable attacking unit that's proving hard to thwart. It's the only unbeaten team in England, and with an enviable depth of talent on the field and on the bench.
"Can anyone stop them? It will be difficult this season," Arsenal manager Arsene Wenger said. "The way they have started, the way they are on a run, the quality they have. They'll be difficult to stop but, you never know."
Despite the victory margin, City needed some luck.
Kevin De Bruyne's opening goal in the 19th minute was followed by a contentiously awarded penalty when Nacho Monreal was adjudged to have bundled over Raheem Sterling. Sergio Aguero converted from the spot, then a third goal from Gabriel Jesus should have been ruled out for offside against David Silva in the build-up.
"If ... they have a decisions for them like that (third goal)," Wenger said, "they will be unstoppable."
Any hopes Arsenal had of a first title since 2004 are fading fast. Arsenal has lost four of six away games in the league for the first time since 1981 and Wenger's team trails City by 12 points.
City has scored 38 goals and won 10 out of 11 games so far. It achieved its latest win after a tough Champions League trip to Napoli where Guardiola's side won 4-2.
"We were so, so tired in moments in the game," Guardiola said, "but we were so strong mentally, mentally strong to keep going, doing it together."
All it took to lift some of the gloom around Stamford Bridge was the return of former manager Jose Mourinho, and a victory over his new club.
Alvaro Morata scored the only goal 10 minutes into the second half, ending a six-game goal drought in all competitions. Morata peeled away from defender Eric Bailly and the striker was completely unmarked 12 yard (meters) from goal when he met Cesar Azpilicueta's pinpoint cross with a powerful looping header.
"We must be pleased for the performance of the team," Chelsea manager Antonio Conte said. "I think we played with a great energy, a great passion, a great enthusiasm."
Unlike perhaps earlier in the week in the Italian capital when Chelsea lost 3-0 to Roma in the Champions League.
"I think tonight I saw a lot of positive things," Conte said, "not only under the tactical aspect but overall the desire, the desire of my players, the will to fight, the will to help each other."
Son Heung-min took over from former Manchester United midfielder Park Ji-Sung as the highest-scoring Premier League player from Asia with his 20th goal for Tottenham.
The South Korea forward pounced on a poor clearance to curl in a shot from just inside the area in the 64th minute at Wembley Stadium as a depleted Tottenham relied on a grittier performance to see off Palace after a slick win over Champions League holder Real Madrid.
Everton was facing its sixth straight loss in all competitions - and fourth under caretaker manager David Unsworth - after goals by Richarlison and Christian Kabasele put Watford 2-0 ahead by the 64th minute.
But three minutes later, Everton's recovery began. Oumar Niasse pulled a goal back, substitute Dominic Calvert-Lewin headed home an equalizer in the 74th and Leighton Baines netted from the spot in stoppage time to complete a 3-2 victory. A first win in nine matches lifted Everton from 19th to 15th in the 20-team standings.
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