Barrie McKay's first goal for Nottingham Forest was enough to secure a 1-0 win for Mark Warburton's side at the City Ground -- but Millwall boss Neil Harris will be wondering quite how.
The winger's spectacular long-range finish, four minutes before half-time, was far from the game's only decisive moment.
Millwall had a host of chances not only to level, but to take away a win of their own -- but this was one of those nights where nothing went for them, as opportunity after opportunity was left begging.
This was always going to be an awkward fixture for Forest, buoyed by the optimism stirred up by new owners and a new manager following Greek shipping magnate Evangelos Marinakis' takeover -- against a Millwall side who had battled their way out of League One.
It was the grit of Harris' Lions that initially got the better of the guile of the home side and Millwall should have been a few goals ahead before the half-hour mark.
George Saville drove a shot into the side netting and Aiden O'Brien's header lacked the power to beat Jordan Smith. Veteran striker Steve Morison did beat the keeper from close range but saw his strike bounce powerfully away off the bar.
Lee Gregory's shot on the turn had Smith scrambling to make an impressive save, after O'Brien had sent a free header a foot too high.
Forest's response saw Ben Brereton creating the room for a shot that was sent spinning into the side netting by a deflection, but Jed Wallace forced another save from Smith as Millwall continued to threaten.
But it was Forest who took the lead when McKay, the £500,000 summer capture from Rangers, conjured up an outstanding long-range strike with keeper Jordan Archer helpless to keep the ball out of the net.
The Reds might have doubled their advantage immediately after the break when McKay rounded the Millwall defence with ease down the left before cutting the back for Brereton, who saw a powerful shot blocked.
Millwall were left kicking themselves again after missing their best chance yet. A poor pass from Smith left Morison with only the keeper to beat. He unselfishly squared for Gregory, who blazed over the empty net.
After Murphy had sent a header wide for Forest, Millwall spurned yet another opportunity. This time it was Wallace who failed to score when clean through, with Smith making an outstanding save.
Morison was celebrating what he thought was an equaliser after squeezing the ball home at the far post but, after a long delay, it was chalked off for offside. To balance things out, Zach Clough saw an effort for Forest chalked off for a marginal offside as well.
Substitute Fred Onyedinma summed up the game when he headed wide for Millwall in injury time.