Watford and West Bromwich Albion shared the points at Vicarage Road as Valerien Ismael's Hornets were held to a draw by his old club in the Championship.
All four goals came inside the first 23 minutes, sparked by Tom Ince opening his Watford account in only the third minute.
But Albion responded in rain-lashed Hertfordshire by scoring twice in three minutes.
John Swift's 14th-minute right-foot free-kick went straight though the Watford wall for his fourth of the season, before Jed Wallace's near-post flicked finish from Darnell Furlong's low right-wing cross gave Albion the lead.