Amid troubled times off the field - Massimo Cellino's proposed takeover at Elland Road was dealt a huge blow on Tuesday when the Italian was found guilty in a Sardinian court of tax evasion, making it unlikely he would pass the Football League's 'owners and directors' test - at least the players did their bit on the pitch by claiming a much-needed win.
Current owner Gulf Finance House Capital subsequently demanded a decision from the Football League over Cellino's takeover by the end of Thursday, although no response was forthcoming as speculation about the club's future rumbled on.
Cellino's lawyers confirmed after the court case he will be appealing against the conviction in relation to the non-payment of taxes on his luxury yacht - a process that could take between nine and 12 months.
First-half goals from Smith and skipper McCormack did provide some good news though, as Brian McDermott's side, unchanged despite a third straight defeat at Burnley last week, won for the first time in seven outings.
Substitute DJ Campbell pulled a goal back for Millwall in the second half, but the Lions have now won only twice in 15 outings since the start of the year and remain in the bottom three.
Millwall boss Ian Holloway made three changes, with the suspended Shaun Williams replaced by Mark Beevers in defence and John Marquis and Scott McDonald starting up front in place of the benched Simeon Jackson and Leeds loanee Steve Morison, who was ineligible against his parent club.
The away side made the brighter start and Jack Butland had to be alert to tip Ed Upson's free-kick behind in the fourth minute.
Jason Pearce was then on hand to snuff out the threat of Fred Onyedinma three minutes later as the forward attempt to convert Upson's low cross from the left.
Tom Lees matched the efforts of his fellow centre-back Pearce to block John Marquis' 10th-minute effort, before the Lions were made to pay for their failure to convert pressure into goals.
Leeds had shown little threat when the impressive Connor Wickham launched a long through into the box, and Smith's well-placed header gave him a 10th league goal of the season.
McCormack was denied when his 35th-minute header from an Alex Mowatt free-kick was scrambled behind, but the former Cardiff man had his 25th league goal of the campaign six minutes later.
A crunching Lees tackle in his own half sent the ball into space down the right flank and the Championship's top scorer cut in unopposed before slotting a low effort between David Forde's legs.
Butland kept out Mark Beevers' low 20-yard effort after the restart and denied Martyn Woolford following a goalmouth scramble, but Leeds might have added a third had Luke Murphy not volleyed wide from 20 yards.
Murphy played in McCormack in the 65th minute, but the striker dragged his shot wide after shaking off the attention of Shane Lowry.
Holloway threw on strikers Stefan Maierhofer, Campbell and Jackson in search of a way back into the match, and Campbell provided it in the 72nd minute by sending a 25-yard screamer into the top corner.
Jackson fed Maierhofer two minutes later, but Butland kept the Austrian's low effort out with his feet as Leeds held on for a welcome victory.
Smith might even have added a third in stoppage time but dragged his effort from 12 yards wide, before McCormack saw his shot cleared off the line by Lowry at the death.