Johnson (right) scores an own goal which gave Everton the lead
By Mandeep Sanghera
Everton secured their first top-flight victory of the season as they ended Birmingham's club record-equalling run of 18 league games unbeaten at home.
The visitors had been denied the lead when Yakubu's shot was cleared off the line by Liam Ridgewell.
But they went ahead when Blues defender Roger Johnson could only prod into his own net from a Leon Osman cross.
Tim Cahill secured the win with a stooping close range header from a Leighton Baines cross in injury-time.
It was a long-awaited victory for the Toffees and a deserved one after they showed the greater ambition and quality at a ground that had become something of a fortress for Birmingham.
Moyes relieved to get first win under belt
The Midlands side had not lost at St Andrew's since a defeat by Bolton on 26 September 2009 but they did not have an answer against an Everton side showing determination and drive.
Everton manager David Moyes had blamed individual errors and poor finishing for his side's problems beforehand, and it was a combination of the two which almost let in Birmingham early on before the Merseysiders were denied the lead at the other end.
Toffees centre-back Sylvain Distin could only loop a clearing header back towards his own goal to let in Cameron Jerome but the Blues striker controlled on his thigh only to half-volley wide from just inside the area.
The visitors had a gilt-edged chance to punish the miss when a slip by Birmingham centre-back Johnson allowed Everton forward Yakubu a strike at goal from 10 yards.
However, Blues keeper Ben Foster smartly got a hand to the ball to crucially slow down the Nigerian's left-foot shot before a sliding Ridgewell cleared off the goal-line.
Everton, with Mikel Arteta their conductor in central midfield, were showing the neater passing play against a Birmingham side looking solid without carrying much of an attacking threat.
Yakubu was also making his presence felt for Everton and he combined well with Osman, who produced a clever turn but sent a strike high and wide.
The nimble and tricky Osman had replaced the injured Steven Pienaar on the left of the Toffees midfield and it was his cross from which Johnson prodded into his own net to give the visitors a deserved lead as they notched their first away goal in the Premier League this season.
It was the slice of fortune the Merseysiders will feel they have been missing and Birmingham will feel their opponents also got the rub of the green when referee Phil Dowd waved away Stephen Carr's appeals for a penalty after he thought he was caught by Everton left-back Baines.
McLeish hoping Birmingham luck will change
Blues boss Alex McLeish threw on strikers Nikola Zigic and Matt Derbyshire in a bid for his side to get an equaliser.
But Everton's defence was expertly marshalled by centre-back Phil Jagielka and stood firm against a Birmingham side who failed to create any chances of note, with Alexander Hleb a peripheral figure as he struggled to provide any creativity or guile.
Cahill's header made sure of the points for Everton as the home side were booed off at the final whistle.
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