Out of almost nowhere, Chelsea have emerged as Arsenal's closest challengers for the Premier League title this season as the London rivals prepare to lock horns at Stamford Bridge this weekend - but is this another false dawn? After all, Enzo Maresca's side found themselves in a similar position midway through 2024-25 only to fall away dramatically in the second half of the campaign. Ahead of Sunday's showdown, though, there is reason to believe the Blues could have staying power this time around.After grinding out wins against Wolves and Burnley, following the customary defeat of Tottenham on the road, Chelsea have - somehow - risen to second in the Premier League table ahead of hosting Mikel Arteta's early-season champions-elect, albeit they are still six points behind their cross-capital foes.Serious doubts, though, remain over their ability to stay the course for the long-term - which are justified given the Blues haven't mounted a sustained title challenge since they last lifted the trophy nine seasons ago, and the backdrop of the club's tumultuous recent history since the Todd Boehly-Clearlake Capital takeover three years ago.It's not long since Chelsea were in a similar position, either; around this time last season they surged into second place behind eventual league winners Liverpool, before failing miserably to deal with the packed festive schedule and sliding back down the standings amid a winter of discontent.This time, though, things feel slightly different, with Maresca's side showing the kind of mettle and big-game aptitude that suggests they could have staying power for the season. However, the visit of the Arsenal juggernaut will be the ultimate test of their credentials at the top of the table.Chelsea's start to the season was inauspicious as they picked up just two wins from six league games, leading many to believe that another top-four finish would be the best that they could hope for. Since the start of October, though, there has been a shift.The sensational late victory over Arne Slot's toiling champions has proven to be the catalyst for a run of eight victories in 10 matches in all competitions, with the alarming home defeat to high-flying Sunderland late last month proving to be an anomaly in what could prove to be a defining period in the west Londoners' campaign.Having dropped points in clashes they were expected to win earlier in the season against Crystal Palace, Brentford and Brighton, the Blues have defeated Nottingham Forest, Wolves and Burnley with relative ease, as well as notching another victory over Spurs in north London in one of the most one-sided 1-0 wins you're likely to see.Of course, Chelsea's young squad reached the latest significant milestone in its progression in the Champions League in midweek, as they utterly dominated the 10 men of Barcelona at Stamford Bridge in a mightily impressive 3-0 thumping that sets them up very nicely for Sunday's top-of-the-table showdown.For Maresca, this developing winning habit is vital to his side's chances of success: "Last year, we were playing in the Conference League, and I said many times that for me personally, if you want to build a winning mentality, there is only one way: winning games. Because otherwise, if you don't win games, it's difficult to convince the players, 'guys, we are building a winning mentality'," the Italian tactician said after Tuesday night's dismantling for the Catalan giants."But when we don't win, it's difficult. So the only way in any competition, Conference League, Champions League this season, Premier League, FA Cup, Carabao Cup, is to win games. It's the only way to build the winning mentality. And I think the Conference League and the Club World Cup last season helped a lot."And now we are trying to do exactly the same. For sure, the players are better players in this moment compared to last season, because we spent more time together."In downing the mighty Barca by exploiting their recklessly high line, Maresca served up another timely reminder of his tactical acumen, but what has been even more impressive of late is his ability to utilise his whole squad without results and performances suffering.No Premier League manager has made more changes to their starting XIs than the Italian so far in 2025-26, with the five he made for the Barcelona game from his team that eased past Burnley taking his tally for the season to a remarkable 102, and it's only November.While he has a core of guaranteed starters in bigger games, Maresca has been able to lean on the likes of Tosin Adarabioyo, Andrey Santos, Jamie Gittens, fit-again Liam Delap and academy graduates Josh Acheampong and Tyrique George in lower-stakes situations - either from the start or as substitutes.They have handled remarkably well without the talismanic Cole Palmer, too, who has made just four appearances this season due to a groin issue and subsequent broken toe. He has, though, been passed fit to play on Sunday. Meanwhile, defensive midfielders Romeo Lavia and Dario Essugo - whose imminent returns will strengthen the group again - have also been sidelined, as well as long-term absentee Levi Colwill.That ability to rotate, and doing so successfully, could well prove to be vital for Chelsea as they fight on four fronts over the notoriously hectic winter period. If they require a two-legged play-off to reach the Champions League last 16 and make progress in the domestic cup competitions, then they face a brutal schedule of as many as 32 games in the next four months.There will, of course, still be question marks over whether Chelsea have the staying power to go the distance and truly challenge Arsenal - who look ominously capable of becoming runaway leaders - all the way until the final day of the campaign, especially given the young group's lack of experience in that department.If we zoom out, the Blues are only one point better off than at the same stage last season, and they have certainly benefitted from unrecognisable champions Liverpool and, to a lesser extent, disjointed Manchester City underperforming considerably to this point.As we've touched upon, their title challenge completely unravelled over the winter period last term before they managed to steady the ship in time to secure a top-four finish on the final day. Even when they were second, Maresca was consistent in his messaging that his team were 'not ready' for a title challenge, although that led some to question whether he had manifested their downturn in form with his pessimistic outlook.It will be very interesting to see how Chelsea contend with the relentless nature of the schedule this time around, but there is a sense that things are different one year on in terms of cohesiveness, togetherness and strength in depth - something the manager has recognised, albeit he maintains it is too early to predict what they are capable of.Speaking in his press conference ahead of welcoming the Gunners, Maresca insisted it would still be premature to judge his side, but admitted things have changed: "I think it's too early in any case. If we win, if we don't win, I think it's too early. We are still, end of November, we are still five, six months to go. I think it's very important when we're going to be in February, March, where we are, and from there we decide and we see if we can achieve something important."The mindset and mood in this moment, for us, is very good. We are doing quite well in the Premier League and the Champions League. We are evolving and growing. This is the best feeling for us."For sure, it's different compared to one year ago because we spent one more year together. Then again, we are at the end of November so it is very early. It's important to be where we are now in March/April and then we will see."The meeting with the seemingly unstoppable Arsenal, who steamrollered Europe's other form team Bayern Munich in midweek, will be the ultimate litmus test of how far Chelsea have progressed, and a barometer of just how far they can go this season. Few fans would have given them a chance of victory a matter of weeks ago, but now it feels like a game that's very hard to call, with the mood around the club far more buoyant.That is thanks in no small part to Maresca's side demonstrating the strides they have made by rediscovering their ability to challenge and win in the biggest games, having beaten Liverpool, Spurs and Barcelona in 2025-26, while they boast further victories over Paris Saint-Germain, the Reds and Tottenham this calendar year."These players, in 16/17/18 months together, they showed many times that they can beat teams," Maresca said. "In the Premier League last year I think we had some good moments where we were able to beat teams. Then PSG, the Club World Cup final. This season, I don't know, against Liverpool or Barcelona. We compete always. Sometimes we are able to win, sometimes we are not able to win. But it's important that we compete against any team."On Sunday, Chelsea's young squad will need to call on all the experience they've gleaned from those encounters if they are to stop Arsenal in their tracks and prove to their rivals and their doubters that they can be the team to push the Gunners all the way this season.