This ought to have been rather easier for Chelsea. Against a Crystal Palace team with nothing to play for – neither Europe nor Premier League survival – they surged into a two-goal lead. At that point, the notion this derby would become nervy for Frank Lampard and his players felt outlandish. They were fluent on the ball and, in the quicksilver Christian Pulisic, who scored the second with a thunderous hit, they can boast one of the division’s in-form players. But the problem for Chelsea is that they must play both ways and, when they are defending, they can look altogether less secure. When Wilfried Zaha unleashed a firecracker than sizzled through Kepa Arrizabalaga, the under-pressure Chelsea goalkeeper, it was the prompt for a contest to break out – one that Lampard’s team would ultimately edge but only after dicing with disaster. Tammy Abraham, on as a substitute, had made it 3-1 with his first goal since 11 January only for Christian Benteke to respond immediately for Palace. Chelsea had the chances for 4-2, most notably through Abraham, who scuffed a shot when gloriously placed. But Chelsea were in no mood to make life easy for themselves, they appeared addicted to jeopardy and, during five minutes of stoppage-time, they almost paid the price. To Lampard’s frustration, Abraham lost the ball cheaply and, following a Zaha cross, Scott Dann thought he had scored with a towering header. Arrizabalaga, though, got his fingertips to the ball to brush it against the inside of the post and away. There was still time for Palace to threaten again through Benteke only for Kurt Zouma to jump into a saving challenge. The full-time whistle brought elation and relief in equal measure for Lampard. His team remain in the driving seat for a Champions League finish. “Kepa should be boosted by that late save – he saved us two points,” Lampard said. “And it was really important for Tammy to score. He is desperate for goals.” Chelsea’s opener had been fortuitous. When Reece James played a pass forward, the Palace centre-half Gary Cahill was the favourite to get to it ahead of Willian. Then he was not. Cahill felt a stab of pain in his hamstring and slipped down in agony, unable even to watch as Willian streaked away to cut back for Olivier Giroud to finish. Should Willian have kicked the ball out? No. For all he knew, Cahill might only have slipped and how silly would he have looked then? Willian was in full flight and it took only a couple of seconds for him to centre for the goal. In that kind of moment, players are simply not wired to stop. Zouma blew a free header from a corner – a glaring miss – before Chelsea took charge, Willian combining with Giroud to play in Pulisic. The American darted outside Joel Ward and unloaded a vicious shot high into the near corner. With the influential Willian forcing Vicente Guaita into a low save, it was difficult to see a way back for Palace and yet the home team found one. It followed a sloppy turnover by James but when Patrick van Aanholt nudged a deflected ball square, it was all about the ferocious power in Zaha’s right foot. The winger looked angry at how the game was going and he channelled the rage into the shot from 25 yards, a celebration of technique which ripped past Arrizabalaga and into the roof of the net. The goalkeeper appeared to have it within his sights but he could do nothing about it – a bad look for him. The feel of the game changed sharply and Palace finished the first half in the ascendancy, with Zaha pepped and Benteke heading at Arrizabalaga. Chelsea needed another goal and Giroud ought to have scored it early in the second half only to send a free header high from James’s cross because Palace, particularly through Zaha, looked capable of hurting them. What had to worry Lampard was how easily Palace were able to play up to his backline. His midfield did not provide enough protection. Chelsea nerves jangled when Zouma had to block from Jordan Ayew after a poorly defended corner. Lampard introduced Ruben Loftus-Cheek and Abraham and, almost immediately, the former played in the latter to shoot low and in off the far post. The exuberance of this Chelsea team in an attacking sense is easy to love. Yet they switched off when Andreas Christensen was beaten too easily by Van Aanholt and Benteke tapped home. The grandstand finish was on.