Chelsea thumped Watford 4-0 in their FA Cup third round replay to set up a classic fourth-round tie against minor league side Scarborough, who upset third divisioners Southend 1-0.

In Wednesday night's other replay, an all-premier league clash, two late goals gave Manchester City a desperately needed 3-1 success at Leicester City to end their 14-game winless run.

Chelsea advanced with two goals from Adrian Mutu, one from Jimmy Floyd Hasselbaink and another from Eidur Gudjohnsen as they atoned for a lacklustre performance at Vicarage Road 11 days ago.

There they had to come from behind twice to draw 2-2 with a side beset by financial problems and now sixth-from last in the first division.

Watford started well, earning four corners in the first four minutes, but went behind to Mutu's first after seven minutes.

Hasselbaink got the second in the 34th minute and Watford's hopes evaporated in the 76th when Mutu scored his second -- the Romanian striker's third in two games having gone 14 without a goal.

Gudjohnsen finished it off in the 84th minute when he put away a cross from fellow substitute Damien Duff, making his first appearance since dislocating his shoulder last month.

Manager Claudio Ranieri was delighted his three strikers had found the target. "It's important for strikers to score. It's like oxygen to them," said the Italian.

He was also pleased with the return of Duff. "When he runs one to one with the ball he is devastating," he said.

Scarborough left it late to set up their dream tie at their 6,250-capacity ground. Striker Mark Quayle got the only goal from close range seven minutes from time.

Their third win over league opposition in the competition this season meant that Scarborough followed fellow Conference team Telford United into the fourth round but it the Yorkshire side who landed the plum tie as the Chelsea game will be televised live earning them a huge payout.

Manchester City, like Chelsea, also twice came from behind to draw 2-2 in the initial meeting and they too took early control of the replay -- albeit away from home.

They struck after 12 minutes when a deep cross by Trevor Sinclair was headed in by French midfielder Antoine Sibierski.

Leicester upped the pressure after the break and equalised with a deflected Les Ferdinand free kick after 73 minutes but Nicolas Anelka seized on some hesitant defending to strike for the visitors in the 90th minute.

Jonathan Macken added a third in injury time to secure the win that earned City a home tie with Tottenham Hotspur.