Actually I thought the defence did very well vs Haaland. He scored his goal, after Gabriel left a big gap and Savinho made a nice pass (superb clinical finish from Haaland btw), and he had a header saved but was largely pocketed in the 2nd half despite playing vs a 10 man team that had flown back from Italy on thursday night and had 2 of the starting back 4 subbed off with cramp for a Polish reserve team player and a 17 year old making his debut.
Haaland's scored a billion goals this season already and when Trossard was sent off surely the feeling was the game was made for Haaland but they largely frustrated him to the extent that he had a go at the aforementioned 17 year old making his debut, and then threw the ball at Gabriel's head after Stones got the equaliser (apparently this is all cool with VAR lol). He then tried to bulldoze Partey. He basically lost control.
I'll let you be the judge if you think that's classy or not, suffice to say the Arsenal defence will remember his actions and he can expect a warm reunion with them at the Emirates next year. Havertz has apparently already said that the foul on Rodri in the first seconds was to remind him of what he said about Arsenal's mentality in an interview at the end of last season, I'd expect Haaland has talked himself into getting smashed at some point in the game at the Emirates. All very unseemly and nothing I'd condone but there are signs he's getting carried away - you'd never see Mbappe do that for example.