BRISTOL, England (AFP) - Middlesbrough were forced into an FA Cup replay after blowing a two-goal lead in their fourth round tie against League One side Bristol City.

Boro appeared to be cruising towards the last 16 of the tournament courtesy of first-half goals from strikers Aiyegbeni Yakubu and Malcolm Christie.

But City responded superbly to a half-time pep talk from manager Gary Johnson, and the fervent support of a 19,000 crowd, by levelling the tie with goals from Richard Keogh and Scott Murray.

Boro´s embarrassment was compounded by the fact that City were far from being at full strength, with strikers Brian Wilson and Wayne Andrews cup-tied and injury and suspension ruling out Phil Jevons, Steve Brooker and Jamie McCombe.

Boro were without the suspended George Boateng and injured duo Mark Viduka and Robert Huth.

But they still managed to get off to the perfect start thanks to some slack defending by the home side.

Stewart Downing was allowed to run unchallenged from virtually the half-way line before sidestepping a belated tackle by Bradley Orr on the edge of the box and firing in a shot that goalkeeper Adriano Basso could not hold.

Following in, Yakubu was able to finish easily from close range and Boro could have soon been two goals ahead, Basso doing well to turn Christie´s shot wide of the post.

The Premiership side did double their lead in the 22nd minute after City had casually conceded possession to Yakubu on the right. The Nigerian released James Morrison and his low cross presented Christie with a simple finish.

Game over, it appeared. But the League One outfit were transformed after the break and fully deserved to pull a goal back eight minutes into the second period, when Keogh got his head to a Lee Johnson free-kick and guided the ball over Mark Schwarzer.

Boro´s Australian goalkeeper inadvertently set up Murray for the equaliser by charging off his line to punch away another Johnson free-kick.

The ball landed at the feet of Murray who showed remarkable presence of mind to lift a lob back over the goalkeeper from 25 yards out.

Boro mounted a late surge but their opponents held out for the draw.