Birmingham boosted their automatic promotion hopes with second-half goals from Darren Purse and Andrew Johnson seeing off Crewe at St Andrews.

Purse struck from the spot in the 61st minute as Birmingham finally made almost non-stop pressure pay, before Johnson sealed their success with a stunning sole strike 11 minutes later.

It was no more than the Blues deserved as they dominated the game - only to find goalkeeper Ademola Bankole in commanding form.

The win was Birmingham's fifth successive league victory and their eighth in the last nine games.

It set them up perfectly for Wednesday's crunch clash with promotion rivals Blackburn here at St Andrews.

But their success ended a run of back-to-back wins for Crewe, who have slipped closer to the relegation dogfight following the setback at Birmingham's home ground.

But they could have few complaints as the margin of their defeat would have been greater if it had not been for the impressive Bankole.

Ironically, Crewe should really have taken the lead as they squandered what was to prove to be their only real chance of the game after just five minutes.

A ball into the box from midfielder Kenny Lunt found the Birmingham defence flat-footed. Lunt's centre fell to unmarked striker Mark Rivers, who only had Birmingham goalkeeper Ian Bennett to beat - but he lifted his shot from six yards over the bar and with his miss went Crewe's hopes.

Birmingham dominated proceedings from then on with Bankole doing well to deny skipper Martin O'Connor and Johnson, who fired in fierce long-range first-half drives.

Bankole was also in the right place to hold a header from Michael Johnson on the stroke of half-time.

When the Nigerian held a 55th-minute half-volley from Nicky Eaden, Birmingham must have feared it would not be their day.

But their pressure finally paid off when Purse powered forward and saw his run halted by a rash challenge from Steve Foster.

But referee David Crick quickly pointed to the spot and Purse fired past Bankole to give the home side the lead.

It ended Crewe's resistance and Johnson capped another exciting display by holding off the challenge of four Crewe defenders with a mazy run before drilling home an angled drive from 12 yards.

Teams:

Birmingham: Bennett, Atherton, Purse, Michael Johnson, Grainger, Eaden (Gill 62), Woodhouse, O'Connor (McCarthy 45), Hughes, Andrew Johnson, Marcelo (Furlong 86).

Subs Not Used: Poole, Holdsworth.

Booked: Woodhouse.

Goals: Purse 61 pen, Andrew Johnson 77.

Crewe: Bankole (Ince 80), Macauley, Walton, Foster, Shaun Smith, Wright, Sorvel, Lunt (Charnock 80), Hulse, Little (Ashton 70), Rivers.

Subs Not Used: Sodje, Street.

Att: 28,042

Ref: D Crick (Worcester Park).