Tom Elliott's double eased Millwall into Round Two of the Carabao Cup on Tuesday night courtesy of a 2-0 First Round victory over Stevenage at The Den.
A relatively uneventful first-half made way for a second which The Lions largely dominated, with the striker's pair sealing victory.
Neil Harris made nine changes from the side that narrowly lost the Sky Bet Championship opener at Nottingham Forest last Friday night, with Jake Cooper and George Saville retaining their places.
The former nearly gave The Lions an early lead in the ninth minute as he connected sweetly with David Worrall's corner-kick, but Joe Fryer in the Stevenage goal expertly tipped the ball over the crossbar.
Fred Onyedinma was presented with an opportunity on 24 minutes as he rose to meet Mahlon Romeo's cross, but the striker tamely headed at Fryer.
Stevenage had their own attempt on goal on 32 minutes, but after Alex Samuel's cross found Matt Godden in the penalty area, a double-stop from Tom King prevented the visitors from taking the lead.
Cooper was forced off through injury three minutes later and was replaced by Lee Gregory, with Shane Ferguson reverting to left-back and Onyedinma to left-midfield.
On 54 minutes, The Lions opened the scoring. Onyedinma's cross found Elliott at the back post, with the frontman rising above his marker to head home for his first goal in a Millwall shirt.
Just over ten minutes later, Millwall doubled their lead and Elliott doubled his goal tally. The cross this time came from the opposite flank in Ferguson, with the former Wimbledon man having the easiest of tasks in nodding home from close range.
Late on, Worrall fired an attempt just over the crossbar and Onyedinma saw his shot saved by Fryer after a sublime piece of skill, but Millwall were unable to add to the score-line, settling for a 2-0 success.
Millwall: King, Craig, Worrall, Thompson, Onyedinma, Ferguson, Romeo, Webster, Elliott, Saville (Williams 74'), Cooper (Gregory 35', (Butcher 70')). Subs not used: Archer, McLaughlin, Wallace, Morison.
Scorer: Elliott 54', 67'
Stevenage: Fryer, Martin, Franks, Wilkinson, Whelpdale (Smith 59'), Pett (Turgott 73'), Samuel, Gorman, Godden (Newton 46'), Henry, McKee. Subs not used: Day, Beautyman, Conlon, Vancooten.
Referee: Simon Hooper