Tommy Mooney strike was good enough for Watford to become only the second team to win at Bramall Lane this season.

Mooney's clinical finish in the 75th minute helped the Hornets to their third consecutive league win.

United did have their chances in a dire game, but Nick Montgomery and James Thomas failed to beat Hornets keeper Alec Chamberlain.

The Blades had the better of the opening chances in the first half. A Paul Devlin cross on 10 minutes was headed down by Shaun Murphy to Thomas - but the young Welsh striker's left-footed shot fell wide from eight yards.

Minutes later Curtis Woodhouse, transfer listed in midweek, fired a fierce first-time drive over the bar after Watford half-cleared a Devlin cross.

The visitors' only real attempt before the break was a weak attempt for Paolo Vernazza - the midfielder's 25-yard attempt was easily saved by United keeper Simon Tracey.

United failed to force too much pressure on Watford, but still managed to create good opportunities.

Michael Brown ran at the Hornets defence before forcing Chamberlain into a fine save from his edge of the box shot.

Then on the stroke of half time Devlin's 25-yard drive again found the grateful arms of Chamberlain.

After the break United were quickly forced into an early substitution, as Montgomery replaced the injured Devlin.

The 19-year-old midfielder made an immediate impact by going close to scoring with virtually his first touch.

Montgomery played a delightful one-two with David Kelly before seeing his first-time shot blocked by Darren Ward.

Watford finally stepped up a gear and began to create chances of their own. On 59 minutes Mooney cut in from the left before firing a 15-yard shot into the side netting.

Watford then had a penalty appeal waved away when Tommy Smith was barged to the ground by United's Rob Ullathorne.

On 69 minutes Montgomery again caused Watford problems after outwitting full-back Paul Robinson. The United forward cut inside the defence, only to see his shot deflected wide.

The game was open for anyone to snatch victory and with 15 minutes of the game remaining Mooney stepped up to fire in his 16th goal of the season.

A Neil Cox cross to the back post fell to Mooney, who smashed the ball back across the face of goal through to United's bottom left-hand corner.

Watford suffered a late scare in the last minute when a 30-yard Montgomery shot was parried by Chamberlain with United's Patrick Suffo looking to follow up - but the Hornets keeper dived bravely at Suffo's feet to clear the danger for a corner.

Teams:

Sheff Utd Tracey, Kozluk, Ullathorne, Sandford, Murphy, Brown, Ford, Woodhouse, Devlin (Montgomery 53), Kelly (Suffo 78), Thomas (D'Jaffo 78).

Subs Not Used: Curle, Uhlenbeek.

Booked: Sandford.

Watford Chamberlain, Cox, Robinson (Steve Palmer 78), Page, Ward, Kennedy (Wooter 72), Vernazza, Nielsen, Noel-Williams, Mooney, Smith (Helguson 73).

Subs Not Used: Hyde, Baardsen.

Booked: Page, Cox, Robinson.

Goals: Mooney 75.

Att: 17,551

Ref: M Cowburn (Blackpool).