The tide of the Premier League title race had already begun to turn when, Wednesday, in the second half of a pivotal clash between its two chief contestants, a big blue wave crashed down on the Emirates Stadium.

Arsenal made mistakes. Manchester City capitalized. The serial champions, off-field baggage and all, swept their way to a 3-1 victory, and to the top of the EPL title race. Pep Guardiola pumped his fists. Mikel Arteta stomped his foot in frustration.

But the Cityzens did not win the title. In fact, they learned a resoundingly clear lesson: That they are in for a battle between now and May 28. That their foes are a new Arsenal, a mentally resilient Arsenal, a fearsome Arsenal.

"They are really, really, really good," Guardiola said postgame.

Amid an uncomfortable London drizzle, the Gunners very easily could have crumbled. They could have reverted to their former selves. Instead, they responded to a masterful Kevin De Bruyne goal with spirit and noise, and then an equalizer.

De Bruyne had pounced on an ill-conceived back pass and lofted City into the lead.

But Arsenal did not despair. Fans answered the goal with defiant songs. Players answered with eager pressing and flowing attacks. Eddie Nketiah won a controversial penalty. Bukayo Saka converted it.

The two then dueled for 30-plus minutes, without separation. Arsenal wobbled, but also threatened. The game hung in the balance.

The hosts were finally punished for their sloppiness in the 72nd minute by Bernardo Silva, and Erling Haaland, and Ilkay Gundogan, and finally Jack Grealish.

They were beaten, thoroughly, by Haaland's clincher 10 minutes later. One corner of the Emirates, the away corner, exploded. The rest fell momentarily silent.

But Arsenal still has a game in hand and three-plus months to go. Perhaps more importantly, this team, and this iteration of the club, have proven their quality and their mettle.

Man City, for the first time in months, is now in control of a likely two-horse race, with Manchester United lurking. But it will indeed be a race. It will be fiercely contested, with swings to and fro. Wednesday was not decisive; it was not a finale. It was the first of many violent swings, the beginning of a few months of more.