Nathaniel Mendez-Laing has given Bluebirds manager Neil Warnock a timely boost ahead of Saturday’s Premier League trip to Everton.
The winger returned to match action in Cardiff City’s 2-0 under-23 home win against Watford on Monday and his final touch was a powerful shot fired his team in front.
Gary Madine netted the second goal after 90 minutes.
Mendez-Laing suffered a knee injury after 10 minutes of the home goalless draw against Huddersfield in August and has been out for three months.
The powerful, hard-running former Sheffield United and Rochdale player started against Watford, looking sharp and fresh.
He played for 68 minutes before being replaced by Jamie Vdale immediately after his goal.
Goalkeeper Brian Murphy, Loic Damour and Madine were the other over-age senior players in the Bluebirds team on a cold night at Cardiff City Stadium.
Captain Ciaron Brown and Jack Bodenham were a solid combination at the heart of City’s back four, while James Waite, full of energy and commitment, was a constant threat to the visitors.
Waite almost opened up the Watford defence after good work by Madine, but he was bundled over on the edge of the penalty area. He jumped up to take the resulting free-kick and forced a flying save from goalkeeper Sam Howes, who pushed the ball away for a corner.
Cardiff played some fluent passing football during the first half of this Professional Under-23 Development fixture and Howes has to make several other smart saves.
Former Everton trainee Tyrone Duffus produced good moments through midfield in a hard fought, physical match.
After a goalless first half Watford went close when centre-back Bodenham was put under pressure when he had possession and slipped a pass back to Murphy.
The goalkeeper hesitated aiming a kick upfield and Watford’s Ryan Cassidy to block the clearance. The ball flew into the air off Cassidy, but dropped wide of the goal.
Mendez-Laing scored when he finished off a sweet move which involved three step-overs on the edge of the Watford penalty area.
Watford defenders tried to block expected shots, but the visitors were cut open by Waite’s exquisitely weighted pass and Mendez-Laing took a touch before smashing his shot into the net from 15 yards.
Madine added Cardiff’s second goal when he headed in at the far post from an excellent left-wing cross.
Cardiff City: Brian Murphy, Cameron Coxe, Ciaron Brown (capt), Daniel Martin, Tyrone Duffus, Loic Damour, Jake Evans, Nathaniel Mendez-Laing (Jamie Veale 68), James Waite, Gary Madine. Subs not used: Ryan Pryce, Warren Burwood (gk), Lloyd Humphries, Laurence Wootton.
Watford: Sam Howes, Andrew Eleftheriou, Lewis Gordon, Ashley Charles (capt), Harry Hudson, Joy Mukena, Harry Forster (Jayden Bennetts 90), Daniel Phillips (Dominic Hutchinson 77), Ryan Cassidy, Kieron Holsgrove (Arjanit Krasniqi 68), Michael Folivi. Subs not used: Ben Tricker, Dante Baptiste.
Referee: Scott Jackson.