Watford began the match with a two-point lead over Wanderers - whose one previous defeat was against Southampton - but Wanderers' victory put them at the top of the table by virtue of this victory. Now, all depends what happens in the teams' final games tomorrow - Watford against Birmingham and Wanderers against Worthing.
Wanderers led 7-4 after three periods before Watford came to life, recovering to 7-6. But that was really the only time the Welsh were in danger. And they were in the clear once goals by Dan Laxton and Steffan Williams restored a 9-7 advantage.
Earlier, Croydon and Worthing maintained their interest in the promotion fight with wins respectively against Cambridge 18-11 and Birmingham 14-6.
Picture (Trevor Hyde): Watford goalkeeper Peter Pickford under pressure from the Welsh attack.