On a day when the memory of the late, great Gianluca Vialli acted as a unifying force, it felt imperative for Chelsea’s players to show pride in the badge. Anything less would have been a betrayal. Chelsea’s fans simply wanted evidence of some heart, anything to suggest another manager is not about to be forced out, and the result was that Graham Potter could feel the pressure lightening a little by the time this flawed contest was done. The relief was immense when Kai Havertz, accepting the responsibility that comes with a £62m fee, barrelled in a header midway through the second half. Havertz’s sixth goal of the season calmed the noise. It brought Chelsea their second win in 10 games and, although it took some fine saves from Kepa Arrizabalaga to deny Crystal Palace a point, victory at least gives Potter some breathing space. Chelsea’s head coach will know there is room for improvement. Potter had remarked that everything has been going wrong in recent weeks, but facing a team as blunt as Palace was too good an opportunity to waste. Tougher tests undoubtedly lie in wait. Even so, with 10 players missing through injury and suspension, a glimpse of the old defiance was welcome. Was it perfect? No. But Chelsea held firm, with Lewis Hall dynamic at left-back, Benoît Badiashile solid on his debut and Thiago Silva magnificent, and they will hope to push on. After all, money is not a problem. Chelsea’s new arrival from Shakhtar Donetsk, Mykhaylo Mudryk, watched his new team from the stands and more incomings are likely before the transfer window shuts. That said, it remains to be seen whether the current hierarchy can fashion a side as watchable as Vialli’s. The angst around Stamford Bridge would subside before kick-off, memories of past glories stirring during the poignant tributes to the Italian. Here was a reminder of a time before anyone had heard of Roman Abramovich or Todd Boehly. Vialli was there when Chelsea were establishing themselves as a force and, as former players gathered to remember the club’s old manager, it was tempting to imagine that the emotion would inspire today’s ailing team. Chelsea needed to display a level of coherence that has so proved beyond them under Potter. There was energy to begin with, but would there be enough quality? The crowd seemed unconvinced. The first groans arrived when Havertz failed to hold the ball up in the 15th minute, heightening the impression that he lacks the strength to lead the line, and the jitters mounted as Palace grew bolder. Michael Olise fancied himself against Hall, a teenager whose attacking zest from left-back is not quite matched by his defensive awareness. Hall was not tight enough to the Palace winger early on. Olise was able to send in a cross and Tyrick Mitchell was unlucky at the far post, Arrizabalaga blocking the left-back’s shot. Chelsea were edgy after making five changes from their defeat at Fulham. With Kalidou Koulibaly dropped, Badiashile partnered Silva in central defence. The foundations felt fragile. Arrizabalaga, who would later save a header from Jeffrey Schlupp, soon thwarted Olise. Watching from an executive box, Mudryk could have been forgiven for wondering whether it was too late to call Arsenal. The Ukraine winger had completed his medical before signing an eight-and-a-half-year deal earlier in the day for an initial €70m (£62m) and Chelsea had made great play on social media of gazumping their London rivals. But Mudryk will not fix everything. Chelsea, who are due to sign the RB Leipzig forward Christopher Nkunku this summer, have bigger holes elsewhere. Cover for the injured Reece James is needed at right-back. More oomph is required in midfield. At least there were some heartening moments for Potter. Conor Gallagher drove forward from midfield, flinging in a cross that Hall almost converted. Creative flashes came from Hakim Ziyech. This was an experimental Chelsea team. There was a first start for the 19-year-old Carney Chukwuemeka and the midfielder tried hard. However, with invention lacking in the absence of the suspended João Félix, the half ended goalless. Chelsea had to find more composure, especially after Palace were forced into a defensive change, Joachim Andersen limping off. But confidence was low and Wilfried Zaha went close the visitors at the start of the second half. Sensing a lull, the crowd bellowed Vialli’s name and Potter introduced Pierre-Emerick Aubameyang. Smart move. With Aubameyang up front, Havertz had more space and Chelsea pressed. After 64 minutes, Gallagher worked a short corner to Ziyech. The Moroccan crossed and nobody could doubt Havertz’s desire when he punished bad marking by powering his header past Vicente Guaita. Palace, meandering in 12th place after four defeats in five games, could not respond despite introducing Jean-Philippe Mateta and Odsonne Édouard. Patrick Vieira’s team have not beaten top-half opposition this season and, while Arrizabalaga tipped Cheick Doucouré’s volley over, they could not ruin Chelsea’s day.