JOIN USWalcott, who netted a hat-trick in a 6-0 home thrashing of Blackpool last week, looked sharp again in a much tougher game at Ewood Park and fired Arsenal ahead with a fine finish after 20 minutes.
Mame Diouf levelled for Rovers on his first Premier League start before Arshavin sealed a deserved victory for Arsenal early in the second half with his strike.
Victory put Arsenal top on seven points from three games but champions Chelsea can reclaim first place if they maintain their 100 percent start to the season at home to Stoke City.
Arsenal's ability to eke out victories away to physical sides like Blackburn has been questioned in recent seasons but they were up to the task on Saturday.
The only blemish on an encouraging day for Arsene Wenger's side was the sight of Dutch striker Robin van Persie limping off with a twisted ankle before halftime.
Van Persie missed a large chunk of last season with an ankle injury although Wenger said afterwards he hoped the player would be back in eight to 10 days.