Despite not losing at Anfield in the League since October of last season, and boasting the best home record in the Premiership during this campaign, a number of Liverpool home performances have started in relatively muted fashion, Rafa Benitez's team coming out of the blocks as cold as the Christmas temperature. Good defending by Danny Shittu and Jay DeMerit stopped Steven Gerrard and Bellamy in their respective tracks on early forays and, indeed, the first shot of the game came from the visitors as Darius Henderson's strike was deflected harmlessly behind after 12 minutes.
But, despite their impressive workrate and defensive willingness, Watford, by the mid-point of the first half, found themselves repeatedly troubled by the mobility and guile of Bellamy and Dirk Kuyt. In the 20th minute, Jermaine Pennant pulled the ball back from the byline and Alonso's shot, from the edge of the area, forced Ben Foster into the first of a number of decent saves.
As Liverpool found their attacking rhythm, Luis Garcia's ball freed Bellamy, whose shot was cleared off the line by the covering Adrian Mariappa. Bellamy then struck a decent chance against Shittu from eight yards and Kuyt's 20-yarder was saved, at the second attempt, by the increasingly impressive Foster.
Even a moment of eccentric keeping by Jose Reina - mistiming a first time volley from a back pass and escaping with nothing worse than a case of acute embarrassment - and a row over an injury to Jordan Stewart and Alonso's reluctance to put the ball out of play, could not impede the flow of one-way traffic. The best save of the half, if not the match, was soon forced upon Foster, by his own player, Shittu. Bellamy's testing low cross struck the defender and Foster showed superb reflexes to parry it to safety.
The final minutes of the first half saw good chances go begging for each team. In the 38th minute, Watford's opportunity came about as uncertain handling by Reina allowed Ashley Young's cross to fall directly to Alhassan Bangura, who should have done better than volley high and over from six yards.
Finally, in what had eventually proved to be a relatively entertaining half, Daniel Agger's spectacular long-range drive was only blocked by Foster, with the rebound falling at the feet of Pennant. The angle, and therefore the opening, was probably slightly more difficult than it appeared but, still, the winger should have hit the target instead of blasting off the mark.
Young opened the second half with an early shot that presented Reina with no problems but, within minutes, Liverpool had the goal they had so desperately sought and which their first-half possession suggested would be along sooner rather than later.
Fittingly, Bellamy was the scorer but the impressive approach play - Kuyt collecting a John Arne Riise throw and Gerrard delivering a perfect, defencesplitting pass - made it an excellent team effort. Bellamy spun through 180 degrees, something permitted him by the lack of an attending marker, before slotting in a perfect finish for his sixth goal of the season for Liverpool.
Credit Watford, however, for the attitude they showed once behind. Young's header from Tommy Smith's cross drew a superb save out of Reina but Bellamy should have doubled Liverpool's lead on 66 minutes. Having been played clear by substitute Mark Gonzalez, he was denied by Foster with only the goalkeeper to beat, with Gonzalez himself heading the rebound wide.
Thereafter there was little to concern Liverpool as they maintained their impressive home record. Jamie Carragher came close with a volley from a 75thminute corner that forced the Watford keeper into the last of a number of decent saves, and substitute Peter Crouch struck the woodwork.
Alonso wrapped it up two minutes from time when Kuyt's cross was cleared only as far as the edge of the Watford area, where the Spain midfielder struck with a fabulous 20-yard shot.
Man of the match: Craig Bellamy
If there is a forward in the Premiership who makes better, more intelligent runs more frequently than Bellamy, then he is a very fi ne player indeed. The Wales forward does so much work without the ball that it is exhausting having to watch him.