For the second time in five days, Everton trailed 3-0 with barely half the game played. Against Manchester United they levelled before losing. At St Andrew's there was no way back, Damien Johnson, Stan Lazaridis and Mikael Forssell scoring to leave Birmingham unbeaten in five and Everton in danger of being dragged into a relegation dogfight.
Lazaridis' goal, a breathtaking individual effort with the interval approaching, effectively broke the visitors. Wayne Rooney did strike a post late on, while James McFadden should have had a penalty after falling under Bryan Hughes' challenge, but Hughes and Forssell also shook the woodwork and Birmingham's biggest Premiership win this season came with an ease that bodes ill for Everton.
David Moyes, the Everton manager, did not disguise his disappointment after an eighth League match without a win. "It was a poor performance," he admitted. "We can't complain about the outcome. We didn't have an awful lot to defend against in that Birmingham didn't have a lot of chances, but it seemed they scored every time they went forward."
Everton have a four-point advantage over the highest of the clubs in the relegation zone, but they also have to play away to Leicester, Leeds and Wolves. Birmingham have no such worries, this success having put them in contention for a Uefa Cup place with Aston Villa, among others, who they face across town in their next Premiership match.
No wonder their manager, Steve Bruce, talked of entering "a vital period", starting with Saturday's FA Cup tie at Sunderland. It is particularly important that their most influential performer on the night, Robbie Savage, regains fitness after limping off with a sore calf.
By the time the Welshman departed, the dye was cast. Birmingham took the lead after only eight minutes following a corner by Savage, who would be involved in all three goals. Thomas Gravesen headed clear, but only as far as Johnson, who speared a low diagonal drive through a congested penalty area.
If Johnson's first goal of the campaign was slightly soft, Lazaridis' second in the 39th minute was hailed by Bruce as "fantastic, probably the best we've scored". Birmingham cleared a corner and Savage played the ball wide to the Australian. From just inside the home half, Lazaridis set off on a run which appeared to have carried him too far to the left of goal for Everton to be threatened. However, after beating Tony Hibbert on the outside, he somehow whipped a ferocious shot back across goal and into the far corner.
Everton rang the changes at the start of the second half, David Unsworth and Ferguson failing to reappear due to illness and double vision. In theory, withdrawing a 6ft 4in centre-forward might make the temptation to play long balls easier to resist. Everton had scant opportunity to test it before Birmingham put the result beyond doubt. In the 48th minute, Alan Stubbs' mistake gave Savage possession. The Welshman rolled the ball to Forssell on the edge of the penalty area and the Finn buried a fierce shot past Martyn for his ninth Premiership goal.
Birmingham, mindful of Everton's fightback last weekend, continued to defend with a diligence that is apparently beyond Manchester United's capabilities right now. Meanwhile, Moyes raged on the touchline against Mark Halsey after a valid penalty appeal in the final quarter-hour, though it would almost certainly have been too late to make a difference.
Birmingham City (4-4-2): Maik Taylor 6; Tebily 5, Cunningham 6, Purse 6, Upson 6; Johnson 6, Savage (Dugarry 4 63) 8, Hughes 6, Lazaridis (John 77) 7; Forssell 7, Morrison 4. Substitutes not used: Bennett (gk), Martin Taylor, Kenna, John.
Everton (4-3-3): Martyn 5; Hibbert 4, Stubbs 4, Unsworth 3 (Pistone h-t), Naysmith 4; Carsley 6, Gravesen 6, Kilbane 5; Rooney 4, Ferguson (Campbell h-t) 3, Radzinski (McFadden 61) 4. Substitutes not used: Simonsen (gk), Linderoth.
Referee: M Halsey (Lancashire) 7.Reuse content