After a gruelling festive period, this was the start of an important week for Cardiff, who host arch rivals Swansea City on Saturday.
The Bluebirds' only league win since early November had come at Watford just over a fortnight ago, while that victory at Vicarage Road had set the Hornets on their losing run.
The two sides' shortcomings were evident in a turgid first half, where Cardiff were the better side by dint of having the only shots on target, with Chris Willock and Calum Chambers testing Watford goalkeeper Jonathan Bond.
The home side were properly on top in the second half, pinning Watford back in their own penalty area with a succession of chances.
Rubin Colwill fired narrowly wide and Perry Ng had a volley saved by Bond, while Cardiff's centre-backs were a handful from set-pieces.
Omer Riza's side eventually got their reward when a succession of ricochets involving Alex Robertson and Chambers ended with the ball at Ashford's feet and the 20-year-old academy product finished coolly with his left.
Cardiff looked to be heading for a precious home win until Watford punctured the hosts' feelgood factor as they equalised with their first shot on target, Bayo heading in from close range from Baah's cross to pinch a point for the visitors and end their losing rut.