Watson's second goal in as many games at the City Ground again proved decisive, having scored the only goal against Barnsley 14 days earlier.

Forest goalkeeper Brice Samba had ensured it remained goalless at the break, scrambling to adjust his footing to parry a Mathias Jensen free-kick that took a heavy deflection.

Watson, whose goal against the Tykes two weeks earlier was his first for almost three and a half years, was enough to extend the Reds' unbeaten Championship run to 10 games.

Brentford's hope of a late fightback took a heavy blow as they finished the match a man down as Sergi Canos limped off after Thomas Franks made all three of his substitutions.

Sabri Lamouchi's side head into the international break behind only the Baggies on goal difference, having collected 13 points from a possible 15 since the last break in early September.

Brentford's first defeat in four games saw them slip to 17th in the table.

A bright and lively first half at the City Ground did not translate into any clear chances from open play for either side, with a curling free-kick from Forest's Tiago Silva that flashed by the post being the closest the Reds came to opening the scoring.

Forest also had an earlier claim for a penalty waved away, when Jensen brought Silva down as he blocked a shot from the midfielder after he met a fine cut-back pass from Lewis Grabban.

The Bees' best moment came from the final kick of the first half, Jensen's deflected free-kick wrong-footing Samba, who recovered well to save.

Watson then thumped Forest into the lead just before the hour, volleying home from 10 yards after a Joe Lolley corner was headed down into his path by Joe Worrall.

Both Forest and the Bees finished with injury concerns, the hosts losing midfielder Samba Sow with a hamstring injury, while Canos was forced off for Brentford added time.

Nottingham Forest manager Sabri Lamouchi:

"I'm so impressed, to be honest. We scored at a good time, and maybe we could have scored a second to finish with less pressure, but what a performance.

"We have been working together for three months now, and for me, that was the best performance.

"The team all fought together, created a lot, didn't give a lot away to the opponents. We deserve this victory, and we deserve to be where we are."

Brentford manager Thomas Frank:

"We're a team that's so much more solid and structured (compared to last season); a team that goes away from home and wants to dominate from the first minute.

"I've only been disappointed with one away performance and that was the defeat to Preston.

"We are definitely on the right track. Defensively we are far better than we were last year, so offensively is where we need to improve because today we lacked quality, sharpness, freshness from our offensive players."