Millwall advanced to Round Two of the Carabao Cup with a 3-1 penalty victory over Gillingham on Tuesday night after the 90 minutes finished goalless.
Tom Elliott, Byron Webster and Shane Ferguson were on target as The Lions finally saw off their Kent opposition.
Neil Harris made 10 changes to the side that took to the field at Ewood Park on Saturday afternoon, with James Meredith the sole survivor.
Ben Amos, Murray Wallace and Jiri Skalak all came in for their first starts in a Millwall shirt, whilst Webster made his first competitive appearance for 11 months, captaining the side.
The first chance of the game came in the fifth minute and went the way of The Lions, but Elliott could not control Conor McLaughlin's superb ball forward. Elliott then chested a ball down three minutes later but skewed his shot wide of the post.
With 11 minutes on the clock The Gills registered their first chance of the evening, but Tom Eaves turned a cross from Bradley Garmston over the bar.
Four minutes passed before the next chance - Elliott knocked down into the path of Ben Thompson, but the midfielder's effort rolled into the arms of Tomas Holy.
McLaughlin was again involved in a promising Millwall move on 21 minutes as his pass down the line fed Elliott - the striker crossed for Onyedinma, but his attempt was well blocked by Holy.
The Northern Irish right-back and Skalak forced saves from Holy as the half-hour mark neared, whilst the Gillingham defence also had to deny Onyedinma and the Czech minutes later. Onyedinma danced into the box 10 minutes from the half-time break as Millwall began to control the game, but his poke across the box was turned away by Holy.
The Gills had the final chance of the first-half as Brandon Hanlan headed Luke O'Neill's cross wide.
On 55 minutes Gillingham had perhaps their best chance to take the lead as the ball fell in front of Tom Eaves around 12 yards out, but his effort was superbly blocked by Meredith. At the other end a couple of minutes later the ball somehow stayed out after a combination of Holy and a defender attempted to clear Ferguson's goal-bound lob off the line.
Eaves' left-foot strike had Amos scrambling on 65 minutes, whilst Ferguson's delightful pass nearly resulted in an own-goal seconds later - Holy stretched to get a hand to the ball, however.
Indecision from Webster allowed Hanlan in during a frenetic period, but his shot crept wide of Amos' post. Just over 10 minutes from time and with penalty kicks looming, Elliott headed over from Skalak's cross.
Another Gillingham chance went begging in the 81st minute as, after creating space and unleashing a shot that beat Amos, Regan Charles-Cook's effort went wide. McLaughlin struck over at the other end seconds later.
Webster blocked from substitute Bradley Stevenson five minutes from time, whilst The Lions' own subs, Jed Wallace, Aiden O'Brien and Lee Gregory, gave Millwall fresh attacking impetus. Elliott's flick-on gave the latter a chance in second-half injury-time, but he was quickly smothered by the Gillingham defence.
And so to penalties - Jed Wallace's first spot-kick was saved by Holy, before Amos repeated the feat from Mark Byrne. Elliott guided his kick to the stopper's right, with Luke O'Neill doing the same. Webster beat Holy - just - before Josh Parker found the upper tier with a dreadful penalty.
Ferguson calmly slotted a penalty into the bottom corner before Amos denied Hanlan to win the game and put The Lions through to Round Two.
Millwall: Amos, McLaughlin, Meredith (O'Brien 74'), Thompson, Onyedinma (Gregory 73'), Ferguson, Webster, Tunnicliffe, Elliott, M. Wallace, Skalak (J. Wallace 83'). Subs not used: Archer, Cooper, Williams, Romeo.
Penalties: J. Wallace (saved), Elliott (scored), Webster (scored), Ferguson (scored)
Gillingham: Holy, O'Neill, Garmston (Fuller 74'), Lacey, Ehmer, Hanlan, Eaves (Wilkinson 76'), Charles-Cook, Reilly (Stevenson 63'), Parker, Byrne. Subs not used: Hadler, Nasseri, Nash, Simpson.
Penalties: Byrne (saved), O'Neill (scored), Parker (missed), Hanlan (saved)
Referee: Charles Breakspear
Attendance: 4,401 (560)