Leroy Lita bagged a hat-trick as Championship leaders Reading came back from 2-0 down to knock West Brom out of the FA Cup in extra-time and deny the Premiership strugglers a fourth round derby with Birmingham.

Albion had made an excellent start thanks to a first-half brace from Richard Chaplow. The 20-year-old had never before found the net in a senior fixture but was able to beat Irish goalkeeper Graham Stack twice before half an hour had passed.

Reading's prolific striker Dave Kitson was rested and Irish partner Kevin Doyle, who has just signed a contract extension to 2009, was on the bench to allow Lita to play alongside another Irish striker, Shane Long.

Chaplow's ninth-minute opener came when he drilled low past Stack after Ronnie Wallwork had opened up the home defence.

Chaplow's second arrived on the half-hour mark and could not have been much simpler; a tap-in from two yards.

Reading needed an early comeback and Lita duly provided that within five minutes of the restart with a smart finish to beat Chris Kirkland at his near post after Martin Albrechtsen had been evaded with a nifty turn.

James Harper set up the equaliser in the 65th minute, with Lita's rising drive from 25 yards perfectly placed as well to give Kirkland no chance.

Lita's hat-trick arrived just three minutes into the second period of extra-time as he fired joyously past Kirkland after last defender Albrechtsen had only half-stopped James Harper's burst into the box.

Birmingham eased some of the pressure on manager Steve Bruce with a 2-0 victory over League Two side Torquay.

Mikael Forssell had Birmingham's best chance of the first half when he hit the post in the 25th minute from Julian Gray's cross.

But there was a sigh of relief around St Andrews when, in the 61st minute, on-loan Chelsea midfielder Jiri Jarosik stuck out his leg to deflect in Neil Kilkenny's shot.

Forssell made the match safe for the Premiership strugglers with the second nine minutes from time.

Middlesbrough avoided an upset in their replay at the Riverside with a comfortable 5-2 victory over Nuneaton.

The Conference North side held out until the 34th minute when Chris Riggott beat the offside trap to hook the ball over Darren Acton and in off the post.

Gaizka Mendieta was fouled in the penalty area by Stuart Whittaker in the 42nd minute Aiyegbeni Yakubu made it 2-0 from the spot.

Stuart Parnaby, Yakubu and Mark Viduka made the game safe after half-time and, although Gez Murphy scored twice in the last 19 minutes, one from a penalty. Middlesbrough now face Coventry in the next round.

Walsall also moved into the next round, overcoming League One rivals Barnsley 2-0. Michael Leary put the home side ahead in the 68th minute, and Kevin James secured the result 10 minutes later.

League Two Cheltenham set up a dream fourth-round tie at home to Newcastle with a 1-0 victory at Chester.

Non-league Tamworth came within 10 minutes of pulling off a major shock but eventually lost 5-4 on penalties to Championship side Stoke.

Tamworth, 21st in the Football Conference, scored through Nathan Jackson in the 42nd minute but Paul Gallagher snatched an equaliser in the 80th minute with a close-range overhead kick.

Michael Touhy saw his effort saved in sudden death and Carl Hoefkens fired home the winner.