Jiri Jarosik and Mikael Forssell ended Coca-Cola League Two strugglers Torquay's resistance with second-half goals to send Birmingham into the fourth round of the FA Cup.

On-loan Chelsea player Jarosik broke the deadlock with his sixth goal of the campaign to establish himself as the club's leading scorer.

Then Forssell scored his first goal since grabbing two against Scunthorpe in the Carling Cup in September.

Blues will be relieved to be in the fourth round, albeit via a far from convincing performance which was nonetheless an improvement on the goalless draw at Plainmoor 10 days ago.

Torquay dragged nine or 10 players behind the ball and threatened only on a couple of occasions from set plays.

But the home side were often laboured and too predictable in their build-up play and made hard work of moving into the last 32.

City looked at their most dangerous when they worked the ball out wide, with Jermaine Pennant and David Dunn in particular sending over a series of threatening crosses.

If they can provide the same sort of service for the rested Chris Sutton and Emile Heskey against Portsmouth in the Premiership at the weekend then the strike duo will have a field day.

City did most of the attacking in the early stages, and former Blues goalkeeper Andy Marriott was called into action for the first time to hold on to a header from Dunn away to his left following a deep centre by Mario Melchiot.

Blues striker Jarosik burst into space after running on to a pass from Neil Kilkenny - but he failed to make proper contact with his left-footed drive which flew harmlessly wide.

Forssell, given a rare start by Steve Bruce, was looking sharp and was denied only by the woodwork after 25 minutes.

The Finnish international moved on to a pass from Julian Gray, and his low left-footed drive struck the inside of the post and rebounded back into play.

Torquay started to come more into the game, and Jo Kuffour had a half-chance after a knock-down from Kevin Hill. But he hit his shot into the ground, and Maik Taylor saved comfortably.

Blues had claims for a penalty turned down just after the half-hour following a challenge by James Sharp on Forssell who had been put clear by Dunn.

Hill could have put Torquay ahead from their first corner. No one picked him up on the edge of the box as he met Steve Woods' cross and volleyed just wide.

The visitors started to believe they could cause an upset, and Maik Taylor had to be alert to deal with a stinging 25-yard free-kick from Morike Sako.

Jarosik then failed to mark Torquay central defender Adam Lockwood who headed just over from another Woods corner. Birmingham retaliated, and Marriott parried away a stinging low drive by Jarosik.

Blues central defender Matthew Upson was yellow-carded on the stroke of half-time for a late challenge on Alex Lawless.

The home side showed more urgency in the early stages of the second period, and Dunn's cross-shot was saved by Marriott at the base of a post.

Forssell's 25-yard drive contained plenty of power but was always going wide of Marriott's right-hand post.

Upson had a shot blocked when Torquay failed to clear a Pennant corner - before Birmingham finally broke the deadlock in the 61st minute.

Marriott punched clear Pennant's cross, but Kilkenny seized on the rebound and hammered in a fierce shot which Jarosik deflected home for his sixth goal of the campaign.

The relief was evident around most of St Andrews, and Dunn almost doubled City's lead with a rasping drive which was only a yard wide.

Jarosik nearly struck for a second time, with Marriott producing a reflex save to keep out Jarosik's volley from Pennant's cross.

But Forssell made sure of victory for Blues nine minutes from time when he headed home another probing cross from Pennant.

Teams:

Birmingham Maik Taylor, Melchiot (Bruce 76),

Martin Taylor (Painter 82), Upson, Gray, Pennant, Kilkenny,

Clemence, Dunn, Jarosik, Forssell.

Subs Not Used: Vaesen, Heskey, Sutton.

Booked: Upson.

Goals: Jarosik 61, Forssell 81.

Torquay Marriott, Lawless, Lloyd, Lockwood, Sharp,

Phillips (Connell 66), Sako (Garner 53), Woods (Hewlett 85),

Kuffour, Bedeau, Hill.

Subs Not Used: Hockley, Villis.

Att: 24,650

Ref: K Stroud (Hampshire).