Robin van Persie continued his extraordinary recent form as Arsenal secured a fourth successive league win - a 3-0 victory over West Brom.
The Gunners failed to turn their dominance into clear-cut chances until the 22nd minute when the Holland international netted his 11th goal of the season and eighth in four matches.
Scorer then turned provider for both Thomas Vermaelen and Mikel Arteta to put the home side out of sight.
The Baggies initially matched the home side with their endeavour, but were undone in the 22nd minute by an exquisite pass from Aaron Ramsey. The Wales international's low ball cut through the West Brom defence and set up Theo Walcott, whose blocked shot fell kindly for Van Persie to net his 29th goal in 28 games this year.
The goal spurred Arsenal into life as they pressed for a second, with Arteta seeing a penalty shout denied before Gervinho was adjudged offside in a dangerous position.
Arsene Wenger's side were still struggling to regularly test Ben Foster, but doubled their advantage six minutes before the break.
Alex Song's ball to the back post was volleyed across goal by Van Persie, allowing Vermaelen to fire home his first of the season.
West Brom were struggling to get out of their own half and only a quick reaction save from Foster thwarted a drive from Alex Song.
With less than 20 minutes remaining, Wenger brought on Yossi Benayoun and Tomas Rosicky and the move immediately paid off in the next attack as Van Persie and Rosicky played a neat one-two before the former teed up Arteta to fire home from 20 yards.
Somen Tchoyi saw a shot blocked by Vermaelen at the other end as West Brom looked to reduce the deficit, although Arsenal were still dominating the majority of possession. Steven Reid tested Wojciech Szczesny with a late header, but the Gunners held out for a comfortable victory and a clean sheet.