A stunning first-half performance helped promotion-chasing Watford blow away out-of-form Bristol City at Vicarage Road in the Championship.
Will Hughes' deflected long-range effort range and Ken Sema's side-footed finish rounded off the perfect half for Xisco Munoz's side.
The Hornets continued to dominate after the break and Sarr deservedly added a fifth, before Philip Zinckernagel tapped in the sixth late on to heap further pressure on City boss Dean Holden.
Coming into this fixture no side had won more games at home in the Championship this season than Watford, while Bristol City had lost their previous six league games on the road.