Jed Wallace's first-half goal settled a tight affair on the opening day of the Sky Bet Championship season as Millwall defeated Preston North End 1-0 at The Den.
The winger expertly struck home Connor Mahoney's cross in the 33rd minute to get The Lions off to a perfect start in 2019/20.
Neil Harris handed debuts to Frank Fielding, Matt Smith and Mahoney, whilst Alex Pearce made his first start - as captain - since signing a permanent deal in the summer.
New signings Bartosz Bialkowski and Jon Dadi Bodvarsson took their place on the bench alongside Tom Bradshaw and Jiri Skalak.
In front of a partisan crowd, The Lions made the early running and had the first effort of the game through Jed Wallace, but the winger's 20-yarder was tipped over the crossbar by Declan Rudd.
Preston then gained a foothold, with Sean Maguire dancing his way into the box, but the ball was cleared behind. After a trio of corner-kicks and a brief spell of pressure, Alan Browne's vicious strike looked to be heading towards the net, but Smith stuck his head out and managed to deflect behind.
With the game descending into a midfield battle, Jake Cooper was the next to have an effort on 21 minutes, but his tame attempt was gathered by Rudd. At the other end, Murray Wallace's teasing cross was just out of reach for Smith and cleared by the North End defence, before Ben Thompson's shout for a penalty-kick went unnoticed by referee Stephen Martin. Maguire then robbed Mahlon Romeo of possession, but the defender recovered to clear.
On 33 minutes, The Lions took the lead, as Mahoney's sublime delivery was struck home on the volley by Jed Wallace, despite Rudd getting a hand to the ball.
The visitors perhaps should have been level five minutes later, but dangerman Maguire headed over from six yards out. The Lions were to suffer a blow shortly before half-time, though, as Fielding had to with draw through injury - Bialkowski his replacement for Millwall's fourth debutant of the day. Yet again, Maguire had the opportunity to draw level in first-half stoppage-time, but he curled just wide.
Preston were fortunate to not be reduced to 10 men on 52 minutes after Andrew Hughes - booked minutes earlier - hauled down Romeo but received no second booking, before the away side could also count their blessings that Martin decided to award a free-kick after Smith was tumbled in the box.
Ryan Leonard was introduced for O'Brien with around 20 minutes remaining as Harris shifted to a 4-4-1-1 formation, with Thompson behind Smith, before the latter was withdrawn to make way for Bradshaw, appearing in a Millwall shirt for the first time since November 2018.
Despite the visitors' attempts to get back into the game and The Lions' want to extend their lead, chances were few and far between as the game reached its conclusion - feeble claims for a penalty after Maguire fell in the box were rightly turned away a minute from time, with Millwall defending well through four minutes of stoppage-time to claim the points.
Millwall: Fielding (Bialkowski 43'), M. Wallace, Cooper, Williams, J. Wallace, Thompson, Smith (Bradshaw 77'), Romeo, Pearce, Mahoney, O'Brien (Leonard 69'). Subs not used: Hutchinson, Ferguson, Bodvarsson, Skalak.
Scorer: J. Wallace 33'
Booking: Williams, Smith
Preston North End: Rudd, Pearson, Clarke, Davies, Browne, Gallagher (Green 73'), Hughes, Bauer, Maguire, Barkhuizen (Stockley 56'), Potts (Bodin 56'). Subs not used: Ripley, Fisher, Storey, Johnson.
Booking: Hughes, Stockley, Browne
Referee: Stephen Martin
Attendance: 14,923 (1,232)