An extraordinary goal by Wesley Hoedt clinched victory for Watford at Hull.
Edo Kayembe gave the visitors an early lead, Scott Twine equalised almost immediately and Watford's Ben Hamer saved Jaden Philogene's second-half penalty before Hoedt's brilliant winner.
The Dutch defender audaciously lobbed keeper Ryan Allsop from 40 yards to secure a win which moved his side closer to the Championship play-off places.
Watford have endured a difficult start to the season under boss Valerien Ismael but have lost just one of their past nine matches.
Their win moved them up three places in the table, to 10th - now just three points behind Hull, who remained sixth despite their defeat.