Birmingham City 2 Torquay United 0

Edgy and nervous, but ultimately triumphant. Birmingham City eased themselves into the fourth round of the FA Cup here last night but only after a performance that raised more questions than answers.

They will meet Reading at the Madejski Stadium later this month and will have to play better than they did in two matches against a Torquay team who are, surprisingly on this evidence, among the worst in English professional football.

Jiri Jarosik, tall and languid but remarkably quick, scored from close range on the hour mark to break Torquay's resistance and give Birmingham breathing space.

Mikael Forssell scored the second late on, brilliantly heading home a cross by Jermain Pennant, to seal the victory but it was not convincing.

Steve Bruce, the Birmingham manager, looked more relieved than enthused.

"We've been here before. Torquay made it difficult in the first half but, once we scored the first goal early in the second half, that settled us down a bit. We were okay after that."

It was clear, certainly with their intentions if not their performance, that Birmingham were taking this tie seriously.

Bruce, an increasingly diminished figure this season, made six changes from the team that lost 2-0 away to Charlton Athletic last Saturday but still fielded a strong line-up.

Jermain Pennant and David Dunn occupied the wing positions, Forssell playing as the lone striker up front, and Jarosik hanging just off the Finland international striker.

It was Forssell's first start since October but one might not have known it, for he was energetic throughout.

In goal for Torquay was Andy Marriott, who enjoyed - or should that be endured? - a spell with Birmingham in 2003. One might have expected Marriott to have come in for a busy evening but there was little to trouble him until Birmingham finally took the lead.

The closest Birmingham came in a ghastly opening period was when Forssell broke clear inside the penalty area after a pass by Julian Gray but struck the ball against the inside of the far post.

It seemed to sum up Forssell's luck, for he was well marked throughout the first half and seemed to spend much of his time on the floor. Birmingham struggled most with the final ball and seemed unable, or unwilling, to take risks.

Torquay, by contrast, seemed to have fewer constraints and, while they had less possession, they played a simple game of pass and move that garnered two half-decent chances. In the 33rd minute, Kevin Hill was unmarked inside the penalty area but volleyed wide from 12 yards. Two minutes later, Morike Sako struck a fierce free kick from 25 yards that Maik Taylor, the Birmingham goal-keeper, did well to save.

It was inevitable that the Birmingham players should be jeered off the pitch at half-time, for they made Torquay look better than a team so far down the football pyramid should look.

It was hard to imagine that 71 places separated the teams, and even harder to accept that Birmingham drew 2-2 with Manchester United only three weeks ago.

Such are the vagaries of football. Such is the fear circulating St Andrew's these days.

And yet Birmingham won. Just. It was not pretty. It was not convincing. But Birmingham will take their place in the fourth round.

The key moment came on the hour when Jarosik, a significant figure throughout, latched on to a cross-shot by Neil Kilkenny to stab the ball home from close range.

On the balance of play, the goal was deserved, but it would be wrong to suggest that Bruce was vindicated. This was still a poor display from Birmingham and this victory, as inevitable as it was, fooled nobody.

After that, Birmingham assumed total control and peppered Marriott's goal with a succession of opportunities. The luckless Forssell came close with a volley in the 64th minute but Marriott turned the ball aside. But Forssell did score with a fine header from close range in the 82nd minute after a fine cross by Pennant.

Birmingham had done just enough.