Jiří Skalák and Jake Cooper scored a goal in each half as Millwall defeated Gillingham 2-1 at Priestfield on Sunday.
Skalák produced a superb dipping finish on the half-volley to give The Lions the lead on 17 minutes but the hosts equalised from the spot early in the second-half. They were level only momentarily, though, as Cooper headed a corner home from close range to secure victory.
Frank Fielding was the first of the two goalkeepers called into action, collecting well after Callum Reilly had fired powerfully at goal following a neat one-two with team-mate Jack Tucker on the edge of the box.
Millwall's first chance of the game was certainly ambitious as Shaun Williams spotted Gills' Joe Walsh off his line, but the midfielder's effort from inside his own half dropped wide of the target.
It took The Lions around 10 minutes to start to settle into their stride, with Mahlon Romeo and new recruit Connor Mahoney looking particularly threatening down the right-hand side.
And it was from that side the opening goal arrived seven minutes later. Ryan Leonard - deep in midfield - spotted the run of Skalák, who latched onto an inch-perfect pass before rifling home a superb finish from inside the area.
Undettered by the set-back, the home team went on the front foot and almost levelled when Tucker sent a looping header towards goal, only for Fielding to produce a superb save and draw applause from the travelling Lions fans behind his goal.
In an end-to-end first-half the chances continued to follow with both Mahoney and Matt Smith - meeting a Shane Ferguson cross with his head - drawing smart stops from Walsh, who then produced a remarkable double save moments later to thwart Millwall's efforts once more.
Neil Harris replaced Matt Smith with Jón Daði Böðvarsson for the second-half and his first appearance for The Lions on English soil began well with some neat touches and combination play.
But it was the hosts who made the first breakthrough of the second period and it came from the spot. Mahlon Romeo was adjuged to have fouled Mark Byrne and a trialist stepped up to slot past Fielding from 12 yards.
The Lions responded by going straight on the attack, only for Walsh to again produce a wonderful save to deny Aiden O'Brien. But he could do nothing to prevent Gillingham going behind just three minutes after levelling, though, as Cooper powerfully headed home from Mahoney's pinpoint corner.
Gillingham made a host of substitutions around the 65-minute mark and the tempo of the match suffered as a result with both sides opting to try and maintain lengthy periods of possession without overly committing men forward.
Millwall switched their shape following the introduction of Billy Mitchell and that tactical change served to assist with the visitors' control of the play as Gillingham struggled to create chances with any possession they did have in the closing stages, which played out relatively uneventfully.
Millwall: Fielding; Romeo, Pearce, Cooper, Ferguson (McNamara, 66'); Mahoney (Burey, 83'), Leonard, Williams, Skalák; O'Brien (Mitchell, 75'), Smith (Bodvarsson, 46').
Subs not used: Sandford, Ransom
Goalscorers: Skalák 17', Cooper 56'
Referee: Mr Gavin Ward