The Alessio Dionisi era at Watford began in unconvincing fashion with a last-gasp 1-0 Carabao Cup victory over League Two side Crawley Town at Vicarage Road.

The Italian, who took over as head coach after the departure of Ed Still at the end of last season, was a relieved man as Marc Bola struck a spectacular long-range winner in the ninth minute of stoppage time.

Watford, twice semi-finalists in the competition, had squandered a stream of opportunities in the 90 minutes with Luca Kjerrumgaard hitting the post early in the second half with one of 36 shot attempts on goal in the first-round tie.

But Bola spared the Championship side the pain of a penalty shootout with a right-foot bullet after a weary Crawley had failed to clear their lines.

Colin Kazim-Richards' men, who beat York City 2-0 on Monday in the preliminary round, had put up heroic resistance in the heat with veteran goalkeeper Vito Mannone outstanding.

He made smart first-half stops from Othmane Maamma and Mattie Pollock and excellent saves after the break from Edoardo Bove and Mamadou Doumbia.

But Watford were guilty of some poor misses too with Spanish Under-21 international Iker Bravo wasting the most glaring chance.

Crawley, who lost 20-year-old striker Gianmarco Di Biase to a leg injury early in the second half, did not offer a great deal in attack.

However, they did carve out one good chance in the first half from a creative set-piece when Charlie Barker arrived unmarked at the back post to meet Stephen Duke-McKenna's ball in, but Federico Ravaglia made a good diving stop in the Watford goal.

When Watford's appeal for a 90th-minute penalty was turned down after Amin Nabizada's shot was blocked by the arm of Jude Arthurs, it looked like Crawley would take the tie through to spot-kicks. That was until left-back Bola's thunderous intervention at the death.