Tom Bradshaw and Mason Bennett found the net as Millwall secured a 2-0 victory at Bristol City in the Sky Bet Championship on Tuesday night.
Bradshaw turned the ball home in the first-half to give The Lions the lead, before Bennett's stylish second-half effort secured all three points for the visitors.
Gary Rowett made four changes from Saturday's 3-0 loss at Middlesbrough, with Murray Wallace, Shaun Williams, Bradshaw and Jon Dadi Bodvarsson all coming in for Alex Pearce, Scott Malone, Ryan Woods and Troy Parrott, who all dropped to the bench.
With less than 30 seconds played, Bennett picked up the ball on The Lions' left-hand side and commenced a powerful run into the penalty area, but his cross was blocked and cleared. Bodvarsson then fed Jed Wallace down the right-hand side on six minutes, but his cross was cut out by Daniel Bentley before reaching Bennett.
The opening stages of the game were fast and frenetic without much direction, leading to passes going astray, but with 14 minutes on the clock came a golden chance for Bristol City - only for them be denied by an outstanding, goal-saving challenge from Ryan Leonard. After Tommy Rowe's free-kick saw the ball land at the feet of Nahki Wells inside the six-yard box, the striker seemingly had the easiest of tasks in putting the ball in the back of the net, but the midfielder launched himself across the striker to poke the ball away from danger.
There were 18 minutes played, however, when The Lions took the lead - and Bradshaw played a major part in the build-up, as well as the finish. A direct run through to the edge of the area saw the striker brought down, and after Jed Wallace's free-kick was deflected into the path of Leonard, his shot from outside the area was turned home by the number nine.
Four minutes later, The Robins nearly found a way to get back into the game, but Wells' free-kick was saved on the line by Bartosz Bialkowski. In an eventful half, shortly before the half-hour mark Bodvarsson and Jed Wallace combined again, but this time the latter's inviting cross was put over by Bennett from a few yards out.
With little in the way of goalmouth action for the rest of the half from there, The Lions went in at the break in front, and they continued to come forward at the beginning of the second-half, but were unable to find a route to goal.
Just after the hour-mark it looked as though Bradshaw's determination would allow him a strike on goal, but as he worked his way inside the penalty area, the Bristol City defence were just able to clear the ball from his path. Millwall only had to wait another six minutes for their next chance on goal, though - and it resulted in the ball hitting the back of the net, as Bennett curled an effort home after Leonard won possession and passed to the attacker.
Diedhiou, who only made his way on to the pitch in the 59th minute, was to last just 20 minutes, as with a little over 10 minutes remaining, he was shown a second yellow card for a high foot on the edge of the Millwall penalty area.
That, plus Bennett's strike, had deflated any potential Bristol City comeback, and with just three minutes remaining it could have been a trio for The Lions, but after Jed Wallace showed pace to beat his marker and poke towards goal, his effort was saved by Bentley.
From there, The Lions saw out five minutes of stoppage-time to claim a first win in 11 matches.
Bristol City: Bentley, Hunt, Nagy (Diedhiou 59'), Martin (Edwards 88'), Mariappa (O'Dowda 59'), Wells, Kalas (Semenyo 73'), Moore, Rowe, Bakinson, Massengo. Subs not used: O'Leary, Z. Smith, Vyner, Bell, Towler.
Booking: Diedhiou, Massengo
Sent Off: Diedhiou
Millwall: Bialkowski, M. Wallace, Hutchinson, Cooper, Williams (Woods 81'), J. Wallace, Bradshaw (Thompson 81'), Romeo, Leonard, Bennett (Malone 73'), Bodvarsson (M. Smith 89'). Subs not used: Fielding, Ferguson, Pearce, Parrott, Burey.
Scorer: Bradshaw 18', Bennett 68'
Referee: David Webb