Full-time from The Den
Free-scoring Forest, who hit five goals in midweek against Fulham, found themselves having to defend in great numbers to deny the lively Lions the maximum points and a victory their overall play arguably deserved.
Millwall bounced back from two successive defeats to hold Championship leaders Nottingham Forest to a goal-less draw in a thoroughly entertaining Den encounter.
Jimmy Abdou moved back into defence with Upson slotting into midfield alongside Williams, and it was the sub who was involved in the action immediately, seeing his rasping drive blocked on the edge of the area.
Millwall were forced to make an early change when right-back Carlos Edwards went down after trying to nick the ball off Antonio. After a four-minute delay to receive treatment, Edwards was stretchered off to warm applause from all four stands and replaced by Ed Upson.
It was Stuart Pearce's side, unbeaten in all nine domestic games this season, who created the first chance in a lively opening with a low 18-yard drive from Michail Antonio that flashed narrowly wide of the post before a Martyn Woolford-led attack was cleared by the visitors.
Forest, fresh from a thumping 5-3 win against Fulham - a result that cost Cottagers' manager Felix Magath his job - came to The Den brimming with confidence and sitting top of the Championship table.
Boss Ian Holloway made four changes to the team that started against Reading in midweek, welcoming fit-again midfielder Shaun Williams back into the fold along with Jermaine Easter, Mathias Ranegie and Martyn Woolford. Richard Chaplow, Byron Webster, Fred Onyedinma and Ricardo were the quartet to make way and instead, took their place on the bench. .
Fuller bull-dozed his way past two challenges after picking up the outstanding Abdou's forward header, but saw his fierce low drive saved by Darlow and Upson fired wide after Abdou's shot had been blocked as the home side continued to look for that vital opening goal.
That proved to be Ranegie's last action of the action and he was replaced by Fuller, with boss Ollie making his third and final substitution just two minutes later, bringing on Magaye Gueye for Easter.
Woolford had a glorious opportunity to break the deadlock on 56 minutes but blasted agonisingly wide of the target from 10 yards and then Ranegie was denied by a brilliant point-blank save by Karl Darlow in the Forest goal as he met Williams' inviting 65th-minute free-kick delivery from the right.
A 20 yard thunderbolt from Williams was headed clear for a corner and with The Den crowd now finding their voice, The Lions drove forward with more purpose and direction than previously.
The visitors were lucky not to be reduced to 10 men five minutes into the second-half when midfielder Henri Lansbury was punished with only a yellow card for elbowing Upson. Mark Beevers (54mins) and Michael Mancienne (55mins) followed Lansbury into the referee's book in quick succession as the game really started to hot up.
Forest themselves had to make a change three minutes before the break when Jack Hunt hobbled off to be replaced by Danny Fox.
Clear scoring chances were at a premium in what was at times a frenetic opening 45 minutes that lacked nothing in effort or commitment, but perhaps that little bit of quality and composure on the ball by both teams in the final third of the pitch.
Assombalonga sliced the ball horrendously off target from 12 yards out as Forest enjoyed a little spell of pressure, but it was The Lions who went close to nicking all three points right at the death when left-back Scott Malone broke into the danger zone, but hit a low effort straight at keeper Darlow.
But it was Forest who suddenly came to life, going close twice in as many minutes with an Antonio header wide from Chris Burke's cross and then Britt Assombalonga's header that eventually found its way into the safe hands of keeper Forde with a trio of Lions players in close attention.
Forde, Edwards (Upson, 7mins), Dunne, Beevers, Malone: Williams, Abdou; Easter, McDonald, Woolford; Ranegie (Fuller, 65mins). Subs not used: King, Chaplow, Gueye, Onyedinma, Webster.
Darlow, Lichaj, Mancienne, Wilson, Assombalonga, Lansbury, Hunt (Fox, 44mins), Antonio, Vaughan, Burke, Tesche (Paterson, 75mins). Subs not used: De Vries, Harding, Veldwijk, Lascelles, Osborn. Lansbury (50mins), Mancienne (55mins), Darlow (78mins)Bookings:
Ref: 12,038 (away 1,676)Att: