The defining moment as Agbonlahor falls under challenge from Johnson
By Jamie Lillywhite
A hotly disputed late penalty from James Milner took Villa level on points with fourth-placed Tottenham after an entertaining midlands derby.
Roger Johnson appeared to win the ball in a challenge with Gabriel Agbonlahor but referee Martin Atkinson pointed to the spot and Milner smashed it home.
Birmingham had largely the better of the chances but found Villa keeper Brad Friedel in unstoppable form.
Villa sealed their third win in a week, their sixth in a row against the Blues.
Apart from the fierce local rivalry, of which there was clear evidence in the build-up as the fans traded insults, both sides had plenty to play for in their 100th league meeting in the top flight.
Villa were keen to pursue their quest for the Champions League on the back of Tottenham losing and Manchester City gaining just a point on Saturday.
Birmingham, meanwhile, were seeking to establish their highest points tally in the Premier League, although their recent form - with no victories from their last seven matches and six defeats from their last seven away games - did not bode well for their chances.
Birmingham deserved better - McLeish
However, instead of producing a dour defensive approach they showed admirable intent in a surprisingly open game and had the first genuine chance as Lee Bowyer slipped a pass through for Sebastian Larsson.
Friedel set the tone for the afternoon, however, pushing him wide, and from an acute angle on the left side of the area, Larsson sliced horribly off target with his left foot.
The Birmingham midfielder soon floored Villa captain Stiliyan Petrov with a fiercely struck free-kick that caught the Bulgarian flush on the forehead.
Villa pressed but the visitors continued to have their fair share of chances, Cameron Jerome through on goal and only denied by the advancing Friedel, who hacked clear.
With Birmingham looking comfortable there followed two chances in quick succession for Villa, but Joe Hart, under the scrutiny of England coach Fabio Capello and his goalkeeping coach Ray Clemence, proved equal to the challenge.
Carlos Cuellar squared to Petrov, whose measured low first-time shot from 25 yards was tipped away by Hart, and the Manchester City keeper, on-loan for the remainder of the season, was alert to beat out a stinging drive from Stewart Downing after he found space and drove through on goal.
Still the goalkeepers remained on top, Friedel keeping out a well-struck long-range effort from former Villa man Craig Gardner that bounced just in front of him, while at the other end a first-time shot from James Collins eight yards out was superbly tipped over by Hart.
Birmingham started the second half brightly and seemed certain to break the deadlock in a remarkable passage of play.
An astute pass from Barry Ferguson found Jerome through on goal but evergreen Friedel, 39 next month, rushed out to smother the shot bravely with his body.
James McFadden collected the loose ball but his shot deflected fractionally wide, then from the resulting corner Liam Ridgewell rose on the edge of the six-yard box but the former Villa defender's header was booted off the line by Downing on the post.
O'Neill convinced penalty was correct
The chances continued for Birmingham and Bowyer saw a low left-footed shot somehow kept out by the redoubtable Friedel.
Villa introduced Emile Heskey and the England striker found himself through on goal but as he tried to lift over Hart the ball brushed the keeper and drifted wide.
But then came the key moment of the afternoon, which left Birmingham bewildered and incensed.
As Agbonlahor surged down the left side of the area Johnson slid in to tackle him, sending the striker sprawling in the process.
Referee Atkinson concluded it was a foul, a decision that caused an even greater split between the rival clubs.
Aston Villa manager Martin O'Neill:
"It's a major victory for us.
"We hung in there all second half. We were second best for a good part of it, Birmingham were very strong in the second half.
"We had played midweek and the previous midweek as well but we hung in and it was a fantastic victory.
"Since the Chelsea debacle at Stamford Bridge (7-1 defeat) we've picked up 13 out of 15 points which shows you our staying power.
Birmingham boss Alex McLeish:
"I shook his (referee Atkinson's) hand at the end as I always do with the refs and said: 'you called it wrong, the big decision and you didn't get it right, I didn't think you were up with the play to make that call.
"He clearly wasn't up with the play. Because of Agbonlahor on the break it is difficult for referees to keep up but it wasn't a clear-cut decision and you can't give it if you're not sure.
"A big crowd can make a big influence, you can hear 40,000 screaming and think 'Oh that must have been a penalty, I'd better give that.'
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