Tom Elliott scored twice in the second half as Millwall eased into the second round of the Carabao Cup with a 2-0 win over Stevenage on Tuesday.
Striker Elliott, making his full debut, headed home twice from close range following good crosses from Fred Onyedinma and Shane Ferguson.
Neil Harris made nine changes to the Millwall line-up that lost on the opening day to Nottingham Forest and they struggled to create any clear-cut chances in the first half.
Jake Cooper's eighth-minute header from a David Worrall corner, which forced a good save from goalkeeper Joe Fryer, was the closest the hosts came in the opening exchanges.
It was the League Two side who had the clearest first-half opportunity in the 31st minute when Alex Samuel squared for Chris Whelpdale but the midfielder could only fire his shot straight at Tom King from inside the penalty area.
Millwall sparked into life after the break and went ahead after 51 minutes. Onyedinma's trickery on the right wing allowed him to stand a cross up to Elliott who powered his header into the top corner from five yards.
And the 26-year-old was at it again after 66 minutes as he asserted Millwall's dominance at The Den.
An over-hit cross from Ben Thompson found Ferguson who was able to deliver to the back post where Elliott was waiting to nod home and double the home side's lead.
Onyedinma almost added a third but his low drive from inside the box was well saved by Fryer.