Arsenal's title challenges have had a disturbing habit of falling apart at this particular venue in recent years, so a convincing victory against an outclassed Birmingham side should add to the positive tide welling up behind Arsene Wenger's unlikely lads.
• Wenger hails Arsenal display
• Premier League gallery A last minute Kevin Phillips equaliser cost the Gunners vital points as they strived to get involved in a top of the table battle last March, while the infamous fixture that ended with Eduardo breaking his leg and skipper William Gallas staging an on-pitch sit-in protest is etched in history as one of the darkest days in Arsenal's recent history. As Wenger's troops arrived in Birmingham with all this baggage in mind, this thumping triumph suggests the team written off by most observers as title no-hopers after they lost to Manchester United at Old Trafford last month are worthy of respect after all. Beating Chelsea at the start of the hectic Christmas fixture pile-up was the first step in Arsenal's rehabilitation, as they looked to confirm their class following a series of setbacks in the first half of the Premier League campaign. They now seem to be growing in belief just as their rivals flounder. Manchester United, their local rivals at City and Tottenham all won on this New Year's Day, but none were anywhere near as convincing as Arsenal, who cruised to three points thanks to strikes from Robin van Persie and Samir Nasri and a Roger Johnson own goal. It was just what Arsenal needed in a week when their all-too familiar failings and their glorious flamboyance have been on display in equal measure, with the glory of the victory against Chelsea last Monday night contrasted by the failure to build on the triumph in the 2-2 draw at Wigan 48 hours later. Any cynic who has dared to suggest Arsenal will win nothing so long as they continue to defend set-plays in such an incompetent manner will have viewed Wenger's rant at his own defenders as they conceded once more from a corner at the DW Stadium during the week as justification for that long-standing gripe. However, their weak underbelly was not to be exposed in this one-sided battle and even though Arsenal floundered when trying to deal with the only threatening free kick they were served up, this is not a day to find fault in a glossy display. Clinical, confident and bristling with that touch of arrogance that champions boast, Arsenal were brilliant for long periods at St Andrew's, yet it could have been so different if referee Peter Walton had followed a different path as he made the key decisions in this game. The free kick he awarded that led to Van Persie's deflected opening goal was very soft, but it was his second moment of generosity towards the Dutch striker at the other end of the pitch that set tongues wagging. Only Mr Walton failed to spot Van Persie's blatant handball in the box as Birmingham pushed for a first-half equaliser, though Arsenal deserve credit for making the most of their fortune and moving through the gears with impressive ease. The second half was dominated by an Arsenal side that pieced together some sumptuous passing moves and manager Arsene Wenger was a vision of contentment as he met the media. "We showed physical courage in this game and we are a team that continues to look stronger," was the opinion of a cool and delighted Frenchman. "We got the ball down, had faith in our method of playing and in the end it has resulted in a win that strengthens our belief. "We have the talent to do well in this title race and having come through a very difficult Christmas schedule with seven points, we have shown great stamina and commitment. Keeping a clean sheet today was also important for us because that is something we have been working on." It is fair to suggest that Arsenal achieved their victory while carrying a passenger in the misfiring Van Persie and while the Dutchman's exuberance delight at scoring from a deflected shot early on was evidence that he was in desperate need of a goal, his first touch was lacking and his finishing was woeful when three more presentable chances came his way before the end of the 90 minutes. Arsenal have waited a long time to see their lead striker return to top form, but he is a long way from that right now and it may be that Wenger's side will not realise their full potential until their No. 10 clicks back into gear. The main focus for Birmingham manager Alex McLeish after this game was Van Persie's contribution at the other end of the pitch, as he suggested the Dutchman's first-half handball altered the course of the game. "Decisions change football matches and we should have had a penalty in the first half when Van Persie handled the ball," was the justifiable moan of the Scot. "If a big decision like that goes against you against a top side, then it is always going to be tough and we found it hard to get the ball of Arsenal for much of the second half. "They were excellent in possession and took care of the game once Nasri fired in the second goal, but this result doesn't change too much for us. Our target is to stay in the Premier League this season and I would take a 17th-place finish if it was offered to me right now." So another layer has been added to Arsenal's growing belief and while the flaws that have undermined them time and again in the last five years may not be banished for good, the title race they were dreaming of joining less than a month ago has welcomed them back onto its starting grid.