Loan signing was Marcus Bettinelli went straight into the Boro line-up between the posts, while Paddy McNair and George Saville started their first matches of the season after returning from international duty with Northern Ireland earlier in the week.

Boro, with the advantage of one more competitive match under the belt than their hosts, looked a shade brighter in the opening exchanges at Vicarage Road, but it was nip and tuck in terms of clear cut chances. 

Then, with 11 minutes on the clock and almost out of nothing, the Hornets struck. A corner was played short, Ken Sema whipped an inviting cross into a dangerous area, and Craig Cathcart stooped to slam home a header and given the home side the lead. It was a moment of quality that served as stark reminder of Watford’s credentials.

The Teessiders responded fairly well to going behind. First, Ashley Fletcher saw a volleyed effort from the corner of the area deflect off a defender and spin narrowly past the post. Minutes later he slipped in strike partner Britt Assombalonga who fired into the legs of Ben Foster from a tight angle. Warnock’s men continued to probe, Jonny Howson delivering a teasing cross into the area that had just too much on it for the stretching Assombalonga.

But the recently relegated home side carried a threat, particularly from set pieces and when breaking at pace. It was the latter which bore an opening for striker Joao Pedro, who forced a smart block from Grant Hall at close quarters. Then a corner, coming in from the opposing flank to that which produced the goal, found Pedro unmarked on the penalty spot - luckily for Boro the 18-year-old forward fluffed his lines.

Fletcher was Boro’s danger man again when, following on from good work from Anfernee Dijksteel, he made space before hooking a volley at Foster. Jonny Howson dragged a shot wide in first-half stoppage time as Boro sought a way to level before the break.

Into the second half, and things were scrappier still than they had been in a nervy first 45. Another half-chance came Boro’s way as Britt Assombalonga spun his marker and shot, Foster putting fingertips on it to send it on its way wide.

The final pass was eluding Boro, and so it proved again when a combination of Anfernee Dijksteel and Djed Spence worked space down the right, but the pull-back from Spence failed to find George Saville.

Assombalonga sent a dipping free-kick Foster’s way, which the Watford keeper opted to tip over, then from the resulting Marcus Tavernier corner Grant Hall got wrong side of his marker but blasted off target under pressure.

Watford at this point appeared content to shield their slender advantage, and the match was stop-start as we entered the final twenty minutes. Debutant Marcus Bettinelli remained untested in Boro’s goal, but time was against the Teessiders.

There was one more chance for Boro, though, and it was a set piece that led to it. Marvin Johnson delivered a free-kick with quality from Boro’s right and Assombalonga stole a yard of space - but he got a slice too much on his glancing header and bounced away from the target.