Troy Deeney scored one and made another in the space of four second-half minutes as Watford maintained their Championship promotion charge at Stoke City.
He then turned architect with a superbly weighted pass into the path of Ismaila Sarr, who ran on to drill a low right-foot shot inside Bursik's right-hand upright.
Steven Fletcher scored from close range to give Stoke hope on 83 minutes, but the Potters never seriously threatened another as their poor league run stretched to one just one win in 10 league games.
It was only Watford's third away league win of the campaign but it lifts Xisco Munoz's men above Brentford to third, level on points with second-placed Swansea City - and within seven points of leaders Norwich City.