Arsenal have to be favourites to win the Premier League now. It is very clear they are going to take some shifting from the top of the table.
The only thing we don't know about Mikel Arteta's side yet is how they will cope with being frontrunners in the second half of the season. But it doesn't look like their inexperience of being in a title race is fazing them at the moment.
Their superb win over north London rivals Tottenham on Sunday was further proof of that.
In the first half we saw their attacking intent and creativity, pressing Spurs to keep them penned in their own half and then capitalising on their mistakes.
Arsenal had more defending to do in the second half but they were just as good without the ball and, when Tottenham did get through, Aaron Ramsdale put in a brilliant goalkeeping performance to keep them out.
I was really impressed with their whole team, from front to back, and it looks like they have got the required steel - plus the bit of bite and hunger - that they will need in the next few months.
Arteta appears to be ready for anything
To be eight points clear after 18 games is a terrific achievement by this Arsenal side - and it's fully deserved too.
Now they have to try to stay there, and many of their players have already learned the hard way how quickly things can change. They fell away in the final weeks of last season, missing out on a top-four finish and a return to the Champions League when it was within their grasp.
But since the start of this campaign I've been saying this looks like a different Gunners team in terms of their mentality, and Arteta and his coaching team have another year's experience too.
Arteta has assembled a talented squad, with an excellent attitude and they look very comfortable with what he wants them to do.
As well as their great will to win, they are strong in every position and they have coped with every injury they have suffered, including Gabriel Jesus who was so important for them at the start of the season, but has not played since the World Cup. Eddie Nketiah has led the line so well, it has meant Jesus has not been missed.
Tactically, it looks like Arteta is ready for anything too. He certainly out-thought Spurs boss Antonio Conte with his gameplan on Sunday, especially in the first half when it seemed like Arsenal had an extra man in every area of the pitch.
Of course there are still some huge hurdles to get over: they still have to play Manchester City twice and, before that, they face a resurgent Manchester United side next weekend.
But every game is a big one when you are top and at the moment they are looking really strong whoever they play. They are clearly full of confidence and right now it feels like they are going to be hard to stop.
Can Man Utd be part of the title race?
The whole weekend went very well for Arsenal - it always helps when things go wrong for your nearest title rivals, like it did for City with their defeat in Saturday's Manchester derby.
The defending champions were unfortunate with United's equaliser, which I felt should have been called offside, and that goal completely changed the game.
I still don't see City giving up their title without a fight though, and they are not the only ones who could still challenge Arsenal from here.
I understand why people are talking about Manchester United again, because they are flying at the moment, on a great run of results, and Erik ten Hag has made amazing progress with his team in a short space of time.
At the moment you cannot rule United out, because they go to Emirates Stadium next Sunday. Win that one, and you'd have to say they are right in the hunt but, on the flip side, if Arsenal turn them over then their title hopes are well and truly over.
Like Manchester United, Newcastle United are only a point behind City, but having played a game more.
I would not count Newcastle as title contenders, though. In fact I still think it would be a miracle if they finish in the top four, despite the problems faced by some of the teams just below them.
Tottenham's defeat on Sunday was good news for Eddie Howe's side, because Spurs are in that chasing pack and they remain a threat. We saw how they ended last season to deny Arsenal a Champions League place.
I also suspect Chelsea will improve after their poor spell in the past few weeks, as their players come back from injury, but Liverpool look miles off it at the moment.
At the moment Jurgen Klopp's side are terrible at the back, with no intensity when they press.
They look a shadow of the side that we are used to seeing at the top end of the table, and I don't see things getting better any time soon - it is going to be a long hard season for them.
I prefer Newcastle to win a cup than finish in top four
Newcastle fans are having a very different time of things right now, of course, and I am enjoying every minute of it.
Howe is doing a brilliant job and he picked up another big result this weekend, with their late win over Fulham.
Right from the start, it felt a bit flat - from the players and even for the fans - which was understandable following the excitement of the midweek win over Leicester that put Newcastle into the Carabao Cup semi-finals.
Newcastle didn't play well on Sunday and needed a bit of luck with Aleksandar Mitrovic's missed penalty, but it was just about getting the three points and it didn't really matter how they got them.
Finishing in the Champions League places would be absolutely fantastic but it is the chance of silverware that means the most to me.
My dream for this season would be a trophy - I'd much prefer the Carabao Cup to the top four.
I'd love to see both happen, obviously, but give me a choice and I'd go for silverware all day long. It's far more important to me.
The last trophy Newcastle won was the Fairs Cup - the tournament that eventually turned into the Europa League - in 1969.
That was before I was born, so it has been a very long wait to see us win something. I hope it is over, soon.
Alan Shearer was speaking to BBC Sport's Chris Bevan.