Cardiff City earned a valuable point in their quest for Premier League status but Watford's battle to secure promotion this season suffered a setback following a tense goalless draw.
On his return to Watford, the Cardiff manager, Malky Mackay, may have seen his side's lead cut to five points at the top of the Championship thanks to Hull City's earlier victory over Middlesbrough, but with David Marshall producing a wonder save to deny Troy Deeney in the second half, a point for the Bluebirds was well worth savouring. For Watford, though, the gap to second is now three points.
"It's our 16th clean sheet of the season," said Mackay. "I thought it was a really dogged and intelligent second half in terms of the way we played and stopped the spaces in behind us. I'm very proud of my group, we've got another point towards our total.
"Watford is a club close to my heart and I was honoured to be manager of this club. I said to Gianfranco [Zola] at the end, I was the manager of Watford, a player at Watford and I'm the manager of Cardiff so I don't think it takes a rocket scientist to work out what I'd like."
Cardiff exerted the greater pressure in the opening stages but they were dealt a blow when the right-back Matthew Connolly was forced off after 10 minutes. It was a move down the right, though, that provided the first real opportunity of the game. Connolly's replacement, Kevin McNaughton, lifted the ball forward to Jordon Mutch who slipped it through to Kim Bo-Kyung, but despite the South Korean's trickery in beating two defenders to advance into the penalty area, his low cross was hacked away.
Watford showed their first glimpse of life after 20 minutes when a swift counter-attack found the fleet-footed Ikechi Anya, but his threatening cross was headed behind. From Almen Abdi's resulting corner Deeney looked to have beaten his marker to the ball, but the striker could not make decisive contact.
Mackay then had to be ushered back into his technical area after Aron Gunnarsson was penalised for what appeared a strong but fair challenge on Abdi in midfield. Mackay was outraged and the fourth official, Lee Collins, was made all too aware of his feelings.
As the half drew to a close Zola had to pull apart Mackay and Giancarlo Corradini, the Watford assistant manager, following a heated exchange. The intensity on the pitch had also been ratcheted up and Cristian Battocchio's speculative drive from 25 yards had David Marshall scrambling across his goal before the ball flew wide. At the other end, Ben Turner's looping header drifted over Manuel Almunia's crossbar.
The clearest opportunity of the half fell to Deeney in the 39th minute. From the left flank Matthew Briggs drifted a deep cross into the area, where Matej Vydra nodded the ball back across goal, only for Deeney to fire over on the half-volley from the penalty spot.
Cardiff came out with renewed intent and Joe Mason had a glorious chance to open the scoring three minutes after half-time. Joel Ekstrand misjudged his clearance and Mason broke free, but after surging into the area his low shot was saved well by Almunia, who was returning after a six-game absence.
Not to be outdone, Marshall then pulled off an incredible stop to deny Deeney in the opposing goal. Ekstrand crossed from the right touchline and Deeney's header seemed destined to nestle into the bottom corner, but at full stretch Marshall dived to his right and somehow tipped it behind.
Zola said: "It's a good point against [a] top of the league [team]. They are a tough, tough team to beat and it is no coincidence that they are in the position that they are. We created opportunities to win the game but their goalkeeper was outstanding. I don't have concerns. We have no pressure, the pressure is on others."