Watford currently lead Nottingham Forest 1-0 after an audacious near-post flick by Gabriele Angella opened the scoring.
The Hornets were struggling to maintain possession for most of the opening half an hour and Forest were initially the better side, without being overly impressive themselves.
But the Golden Boys, like on Saturday, started in a 3-4-2-1 formation and did carry a counter-attacking threat.
Forest had failed to pick up Angella at set pieces on three previous occasions before a corner to the near post just after the half-hour mark was back-heeled goalwards by Angella and the ball went in with the assistance of the crossbar.
Troy Deeney nearly added a second soon after when his first-time volley from ten yards hit the side-netting.
Forest did have chances. Danny Collins saw his header rebound off the crossbar early on and Jamie Paterson also had a low shot saved with the game goalless. Defender Greg Halford, who again started as striker, should have tested Manuel Almunia when he sent a free header over the bar.
Forest: Darlow; Lichaj, Lascelles, Collins, Harding; Jara, Moussi; Paterson, Reid, Abdoun; Halford.
Subs: De Vries, Majewski, Mackie, Henderson, Derbyshire, Cox, Tudgay.
Watford: Almunia; Doyley, Angella, Ekstrand; Faraoni, Murray, Battocchio, Pudil; Anya; Forestieri, Deeney.
Subs: Bond, Cassetti, Merkel, Abdi, Bellerin, Hall, Fabbrini.
Follow the second-half action here.