Dany N'Guessan bagged a debut goal as Millwall booked their place in the Carling Cup second round with a deserved victory at Plymouth Argyle.
N'Guessan, signed on loan from Leicester City on Monday, provided the decisive strike on 14 minutes with a crisp finish from John Marquis' flick on to seal success.
Although it took a fine save from Lions keeper Steve Mildenhall to deny 16-year-old sub Matt Lecointe a leveller right at the death, there could be few complaints in the Plymouth camp at the final result.
This was an efficient, effective display by a Millwall side showing nine changes to the team that started at Reading on Saturday.
As promised beforehand, manager Kenny Jackett utilised his squad to the maximum with only stand-in skipper Tony Craig and John Marquis surviving from the XI that kicked off the campaign at the Madejski Stadium.
A quartet of players made their Lions debuts, with Therry Racon and Jordan Stewart taking their place in midfield, N'Guessan up front alongside Marquis and Mildenhall replacing David Forde in goal, the latter of whom is away on international duty with Ireland.
Millwall carved out an early chance when Chris Hackett intercepted the ball on the right, slipped a neat pass to debutant N'Guessan whose low shot was comfortably held by Jake Cole in the home goal.
The Greens responded immediately with a quick break on the left flank resulting in Robbie Williams' delivery from the byline dropping onto the roof of the net.
Hackett forced a solid stop from Cole after seven minutes, picking up a delightful sliderule pass from right-back Smith and striking a crisp low shot that the keeper held at the second attempt.
The Lions didn't have to wait long to break the deadlock though; Mildenhall's long clearance was flicked on by Marquis and N'Guessan kept his cool to stroke home a 14th-minute opener.
Minutes later Marquis teed up Scott Barron, and the left-back's fierce drive flashed over before the impressive young striker then played in N'Guessan, whose angled shot fizzed even closer to the target.
New boys Racon, Stewart and N'Guessan combined on a quick counter-attack that nearly produced a second goal Millwall's domination deserved, but defender Stephane Zubar was able to divert the ball back into keeper Cole's hands with Marquis waiting to pounce.
The busy Greens goalie was then on hand to deny Darren Purse, whose towering header from a deep Hackett freekick was clawed away at the far post just before the break
The second half continued in much the same vein as the first with Plymouth not lacking in effort, but simply unable to make any real impression going forward leaving Lions keeper Mildenhall a virtual spectator.
At the other end N'Guessan's glancing header from Smith's cross flew narrowly off target, whilst Racon did get the ball in the bacl of the net around the hour mark but his effort was disallowed for a foul by Marquis on Stephane Zuba.
N'Guessan's textbook downward header smacked the bar and then Stewart was flattened as he retrieved the loose ball, but referee Keith Stroud waved away what really did appear to be a nailed-on penalty.
The lively N'Guessan was denied again when he latched onto a magnificent drilled forward pass from former Argyle midfielder Jimmy Abdou, seeming to get a little nudge in the back from Ladji Soukouna as he shaped to shoot.
Lions stopper Mildenhall was finally called into action 11 minutes from time with with an athletic save at full stretch to pluck Williams curling 20-yard freekick out of the air.
Then in the dying seconds Mildenhall ensured that it was The Lions who will take their place in the second round draw, brilliantly blocking a stinging strike from teenage sub Lecointe.
Although an additional five minutes of injury time were held up by the fourth official, Jackett's men had the experience and expertise to run the clock down in comfortable fashion and hold on for victory.
Plymouth Argyle: Cole, Williams, Zubar, Nelson, Daley, Walton, Hitchcock, Soukouna (Copp, 73mins), Sims (Lecointe, 59mins), Gibson, Hourihane. Subs not used: Larrieu, Vassell, Pearce, Harper-Penman.
Bookings: Hitchcock (15mins), Gibson (40mins), Hourihane (45+2mins), Walton (86mins)
Millwall: Mildenhall, Smith, Barron, Racon(Mkandawire, 70mins), Purse, Craig, Stewart, Abdou, Marquis ,N'Guessan (Bouazza, 78mins), Hackett. Subs not used: Allsop, Dunne, Robinson, Henry, Ward.
Booking: Abdou (26mins)
Scorer: N'Guessan (14mins)
Ref: K. Stroud