Bolton put their relegation worries to one side as goals from Ryo Miyaichi and David Ngog secured an FA Cup quarter-final place at Millwall's expense.
Arsenal loanee Miyaichi showed why Gunners manager Arsene Wenger rates him so highly when he curled the ball into the corner in the fourth minute.
Just before the hour, Ngog's left-footed shot was too strong for Steve Mildenhall as Bolton went 2-0 up.
Adam Bogdan then made a double save to thwart Harry Kane and Darius Henderson.
Japanese forward Miyaichi, who only turned 19 in December, joined Bolton in the January transfer window and manager Owen Coyle will no doubt be hoping he will have the same galvanising effect that Arsenal midfielder Jack Wilshere had on the Trotters when he arrived on loan in 2010.
The teenager latched on to Sam Ricketts' quick free-kick and after holding off Alan Dunne's challenge finished with superb composure.
Fabrice Muamba and Ngog also had good first-half chances, while Millwall failed to test Bolton goalkeeper Bogdan despite the ample possession they enjoyed.
The closest the Lions came to an equaliser before the break was when the Trotters' Iceland international Gretar Steinsson sliced his attempted clearance from Liam Feeney's cross over his own crossbar.
Just after the interval Paul Robinson met Scott Barron's 49th-minute corner with a header but did not make sufficient contact and the ball sailed wide.
It was then Robinson's poor clearance at the other end that led to Ngog's goal, the former Liverpool man's strike effectively killing off any hopes the hosts retained of turning the tie round.
Tuncay capitalised on the error to feed Ngog and the Frenchman beat Mildenhall, who could only get a hand to the ball.
Liam Trotter's long-range effort did test Bogdan, who soon after made a point-blank save from Kane and then Henderson as the rain started to lash down.
Andy Keogh came close to connecting with a deep cross in a final hurrah from Millwall, before Miyaichi, who had visibly tired during the second period, was replaced by Chris Eagles.
Keeping possession well, the visitors finished strongly, with Ricketts powering to the edge of the box before shooting wide.
Millwall manager Kenny Jackett: "To give a Premier League side a start like that is disappointing and gave them something to hold onto - basically after that their game plan was to sit deep.
"We had a lot of good possession and some good moves without being able to get that goal.
"There were some key moments - Gretar Steinsson nearly scoring an own goal in the first half and then a good double-save by the goalkeeper.
"We need one of those moments to break for us because that would have obviously got us back into the game."
Bolton manager Owen Coyle: "Ryo Miyaichi showed what a talent he is.
"There's other stuff he can learn, but he's brave and tough - he stood up to some of the treatment he got - and he always plays with a smile on his face, which I absolutely love.
"In football terms he is a baby, a kid. I saw when Arsenal brought him in and then watched him on loan at Feyenoord last year, and he always caught my eye.
"I spoke to Arsene a few times about him and did everything I could to get him to the football club."