Marlon King's 17th goal of the season two minutes from time kept Watford's hopes of automatic promotion alive at the expense of play-off hopefuls Cardiff at Vicarage Road.

Jeff Whitley looked to have earned Cardiff an unlikely point with their only shot on target to cancel out Malky Mackay's opener, which came after 69 minutes of one-way traffic.

But King, the Coca-Cola Championship's top scorer, capped another impressive performance with a deserved winner after Riccardo Scimeca's poor backpass to leave the Hornets seven points behind second-placed Sheffield United.

Both teams were unchanged from wins last weekend, with the exception of Watford goalkeeper Ben Foster, who returned from suspension at the expense of veteran Alec Chamberlain.

Highly rated Cameron Jerome lined up in attack for the visitors after passing a late fitness test on a groin injury, while the City defence boasted two former Hornets in Neil Cox and Neal Ardley.

Watford went straight on the attack and forced a corner in the first minute, from which Hameur Bouazza fired narrowly wide of Neil Alexander's left-hand post.

Chris Eagles, who scored from the halfway line against Brighton last week, resisted the cries of "shoot" from the home faithful to send in a couple of fine curling crosses which also caused mild early panic in the Cardiff area.

The Hornets were unlucky not to go ahead after 12 minutes, when Bouazza's cross was headed onto the crossbar by Mackay and Alexander gathered Jay DeMerit's follow-up.

Mackay then stabbed the ball just wide after a low King cross found its way to him through a crowded goalmouth, before the veteran Scot forced a fine point-blank save from Alexander with another header from Lloyd Doyley's long throw.

Alexander kept the hosts out once again with a superb save from Bouazza's flick, and although Mackay was first to the rebound his shot was hacked off the line.

Cardiff finally registered an effort on goal as the interval approached, when Darren Purse headed a Jason Koumas corner over the top.

Matthew Spring saw a low shot well saved by Alexander before Eagles fired wide after a marauding run by King as Watford continued to press after the break.

And they finally got their reward in the 69th minute after Alexander had pulled off another reaction save from Ashley Young's close-range shot. The ball fell to Bouazza, who chipped the ball to the far post from where Mackay nodded it home.

But the hosts were stunned eight minutes later when Whitley latched onto Koumas' long ball, raced clear and coolly fired past Foster for his first goal since May 2004 for Sunderland.

However, Watford were not to be denied and King latched onto a woeful backpass from Scimeca, rounded the exposed Alexander and put the ball into an empty net.

And the Hornets survived an injury-time scare when Koumas thumped a free kick against the post and Foster saved Purse's follow-up.