Dean Smith was left bemoaning individual errors as the Norwich head coach admitted after a Boxing Day thrashing by Arsenal that standards had “dropped massively”. A brace from Bukayo Saka either side of a rare Kieran Tierney strike had Arsenal on course for three points before a late Alexandre Lacazette penalty and a goal for the substitute Emile Smith Rowe secured a comfortable 5-0 victory. The win leaves Arsenal six points clear in fourth place – albeit with Spurs having three games in hand – although they later learned Tuesday’s game against Wolves at Emirates Stadium has been postponed due to high numbers of Covid cases for the visitors. While Arsenal continued a decent run of form, Norwich remain rooted to the bottom of the table. Smith was left unhappy with the costly mistakes that saw his side fall short of the levels he has demanded since replacing Daniel Farke. “It was very difficult to be honest, I didn’t see that coming,” Smith said. “The last game [a 2-0 defeat against Aston Villa] the first half was poor but two games ago we were going toe‑to‑toe with Man United and had fans out of their seats. “This was just as flat a performance as we have had and it was littered with unforced errors. We’ve got to be better than that and we are better than that, unfortunately the standards have dropped off massively from the Manchester United game, there are reasons for that but I’m not here to make excuses.” Those reasons are likely to be a mixture of injuries and positive Covid cases, with Smith conceding he faces a “bigger job” keeping Norwich up because of the state of his squad. Mikel Arteta was in a much brighter place post-match. “I’m very happy,” the Arsenal manager said. “It is not easy to win away from home in this league, the way we performed and how dominant we were, it was really impressive. “I think in general, collectively and individually, we had some big performances and you don’t win 5-0 away from home if you don’t do that so I am happy with all the boys.” Arteta also highlighted the progression made over the course of the season, having beaten Norwich 1-0 in September when it was his side – and not the Canaries – who kicked off at the foot of the table. Asked if the belief his players were showing was a result of the different feel within the squad, he replied: “Yes, probably. The direction the team is taking, how we are growing, the understanding between the players, the unity we have been showing in general and the support we have been getting in every ground is very much linked with the way we can transmit and the way we want to play. “That is what we are here for, to create enjoyment and if they enjoy it I’m sure people will enjoy watching them play, they really like each other, they enjoy playing with each other and you can see that.” Saka set the tone early on, collecting a pass from the impressive Martin Ødegaard before slotting past Angus Gunn – the goalkeeper in for the regular first-choice, Tim Krul, one of a number of positive Covid cases in Smith’s squad. Arsenal were without Calum Chambers, Ainsley Maitland‑Niles, Cédric Soares and Takehiro Tomiyasu because of Covid but they were not missed. To their credit, Norwich battled for periods of the first half but the game slipped away. As half-time approached, another fine ball from Ødegaard allowed Tierney to break into the box and fire in low across Gunn for his fourth goal for the club. There never looked like being an inspired second-half comeback for Norwich. Saka’s second goal in the 67th minute was a fine finish as the England winger cut inside Brandon Williams before striking from the edge of the box to secure the win. Lacazette was then bundled over by Ozan Kabak six minutes from time and he tucked away the resulting penalty before Smith Rowe scored off the bench for the second league outing in succession.