CHELSEA left it until three minutes into stoppage time before seeing off a gallant Watford at Vicarage Road.

Salomon Kalou scored with virtually the final kick of the game from Andriy Shevchenko’s cross to at least take the title fight to another week. While Chelsea’s season of internecine conflict has followed a script of outlandish manufacture, few have accused Watford of losing touch with reality. Last week brought Aidy Boothroyd’s second anniversary as the club’s manager, celebrated according to the pragmatic northerner with “a couple of sandwiches and a bag of crisps in the canteen”.

If much of his team’s football has been of the same economy brand it has been for understandable reasons. Boothroyd’s most effective striker, Marlon King, was lost to injury in October. His most creative influence, Ashley Young, sold to Aston Villa in January. Even with both of them in place for the entire campaign it would have been a struggle.

If that places Jose Mourinho’s struggles in perspective, he had a new problem to deal with in replacing Arjen Robben, victim of a torn meniscus last week. Using Shaun Wright-Phillips on the right-hand side of his midfield diamond did not prove an effective solution at first.

With John Terry knocked to the ground by an unintentional Darius Henderson elbow in the first minute, the away defence was nervous. Tommy Smith, playing with unexpected freedom at the head of Watford’s diamond, had a justifiable claim for a penalty when his right-wing cross was palmed down by John Terry from a distance far enough away to be avoidable. Nothing more complicated than a Gavin Mahon long throw provoked a panicked back header that Steve Kabba met with an overhead kick and Petr Cech parried. Soon Smith was accelerating beyond Terry and into the area only to be halted by Ricardo Carvalho’s fine tackle. At the corner Chelsea permitted the ball to bobble around the goalmouth again until Henderson slammed it over the crossbar.

Usually so accustomed in holding possession until their opposition cedes chances, Chelsea’s short passing suffered on the uneven surface and their long passing lacked accuracy. Opportunities were sparse. Frank Lampard, broken right wrist in plaster and bandage, forlornly appealed for a penalty following an edge-of-the-box tangle. Then Wright-Phillips worked himself into space to shoot at Ben Foster, but his strike was gathered.

Only with a third of the match gone did the visitors begin to pose a genuine threat as Lampard headed on for a Didier Drogba volley stymied by excellent goalkeeping. A minute later Carvalho’s ability to summon the unconventional pass saw him loft the ball on to Michael Ballack’s head for an effort that diced with Foster’s upright. An agile double save was required to foil Ashley Cole and Shevchenko.

The half-time ovation from the yellow section of Vicarage Road was more intense than that following some Stamford Bridge wins; Mourinho’s interval response was more typical. Off went the ineffective Geremi and the unusually inattentive Claude Makelele. In came Paulo Ferreira and Kalou as the coach pushed his diamond from the midfield to the attack, asking Ballack and Lampard to hold.

It was not immediately effective, the first chance of the half falling to Watford from another scrappily defended long throw that Kabba angled wastefully over.

When Smith’s sprint on goal and tussle with Ferreira was incorrectly judged illegal by Uriah Rennie, Mourinho and Boothroyd ended up in touchline debate. If it was about tactics, Mourinho agreed his weren’t working, bringing Jon Obi Mikel on before the hour mark.

Star man: Salomon Kalou (Chelsea)

Player ratings. Watford: Foster 7, Chambers 6, Shittu 7, DeMerit 7, Stewart 6, Mahon 7, Francis 6, Rinaldi 6, Smith 7, Henderson 7 (Priskin 69min), Kabba 7 (Bouazza 81min)

Chelsea: Cech 7, Geremi 5 (Ferreira ht 6), Carvalho 6, Terry 5, A Cole 5 (Mikel 58min, 6), Makelele 5 (Kalou ht 7), Wright-Phillips 5, Lampard 6, Ballack 5, Drogba 5, Shevchenko 5

Scorer: Chelsea: Kalou 90

Referee: U Rennie

Attendance: 19,793