Fulham returned to winning ways in emphatic style in south London this evening as they put a shaky first half display behind them to inflict Millwall’s first defeat since New Year’s Day by scoring three second half goals without reply at the New Den. Slavisa Jokanovic’s side were put under real pressure as the Lions made most of the early running, roared on by their passionate home crowd, and could have easily been behind by the break but the Whites showed the kind of resilience that has typified their club record unbeaten run as goals from Ryan Sessegnon, a superb strike from Kevin McDonald and Aleksandar Mitrovic’s after the interval transferred the pressure back onto Cardiff in the race for second place.

The Whites knew they would be in for a severe test at the Den this evening with Neil Harris having taken his unfancied side from a relegation battle earlier in the season to the cusp of the Championship play-offs in one of the division’s most remarkable managerial jobs. The home side set about their visitors from the off, perhaps eager to examine whether there was any hangover from remaining from Fulham’s failure to cling onto all three points against Brentford last weekend. Millwall, with the physical threat of their potent front two – Steve Morison and Lee Gregory to the fore – were making inroads almost immediately and might have mustered the dream start with a little more fortune.

Marcus Bettinelli did magnificently to touch a Jake Cooper header from Ben Marshall’s deep corner onto the crossbar, but Fulham looked rattled by Millwall’s incessant pressure. They looked especially vulnerable when Marshall was able to whip balls in with his right foot from the left and only escaped shortly afterwards when referee Andre Marriner disallowed George Saville’s goal for a foul by Jed Wallace on Matt Targett. Another Marshall cross bent wickedly away from Bettinelli and Fulham were indebted to Tim Ream who cleared from just in front of his own line when Wallace seemed to set to give the Lions the lead.

Those narrow escapes seemed to briefly galvanise the visitors. Mitrovic headed a difficult chance over the bar from a Targett cross and, from Fulham’s first sustained spell of possession, Stefan Johansen sent Sessegnon clear down the left but his low cross was scrambled away from Mitrovic by the covering Cooper. Fulham’s presence in the Millwall box was fleeting and it might well have been unjust had Targett’s rising drive flew under the crossbar rather than clipping it in the last minute of stoppage time, as the home side squandered further chances before the break with Morison heading over another dangerous delivery from Marshall.

Fulham recovered their composure during the half-time interval and needed no more than forty seconds after the restart to take the lead. Mitrovic found a rare pocket of space in front of the Millwall back four that gave him the time to spin and fire a speculative shot goalwards. Jordan Archer spilled the Serbian’s effort and haring in was Sessegnon to steer home his fifteenth goal of the season in the blink of an eye.

The Whites sensed blood and moved quickly in for the kill. Johansen passed up a glorious chance to double the lead when he was sent through on goal moments later, but the vital second goal arrived, albeit from an unlikely source. Scottish midfielder Kevin McDonald, more lauded for his crucial interventions at the other end of the pitch than his goalscoring prowess, was allowed to drift onto his right foot 25 yards out and curl home a superb effort to double Fulham’s lead. It might have been three when Sessegnon surged away from the Millwall defence but sent a first time narrowly wide of the far post.

With Fulham keeping the ball impressively in the Millwall half, Harris’ side struggled to match the ferocious intensity of the first period. Tom Elliott and Tim Cahill were thrown in as the home side sought a foothold in the contest, but although Elliott won a few headers, Cahill’s contribution matched Millwall’s increasing frustrations. The Australian veteran was fortunate not to see a straight red for swinging an elbow at Ryan Fredericks before being booked for a late challenge on Tom Cairney.

Bettinelli didn’t have to make a save of any note in the second half and Fulham’s confidence was so high by the end of the evening that Tomas Kalas, introduced to strengthen their defence, found himself striding deep into Millwall territory with the ball at his feet. The Czech centre half had travelled more than 30 yards by the time he laid it off to Mitrovic and the Serbian picked his spot in the top left corner of Archer’s net. This was a performance ruthless enough to make Jokanovic purr with satisfaction – and Fulham will now be hoping Cardiff will stumble with the finish line in sight.

MILLWALL (4-4-2): Archer; Romeo (O’Brien 87), Meredith (Cahill 77), Hutchinson, Cooper; Williams, Saville, Wallace, Marshall (Elliott 65); Morison, Gregory. Subs (not used): Martin, Shackell, Tunnicliffe, Onyedinma.

BOOKED: Hutchinson, Wallace, Cahill, Gregory.

FULHAM (4-3-3): Bettinelli; Fredericks (Christie 90), Targett, Odoi, Ream; McDonald, Johansen, Cairney; Piazon (Kalas 82), R. Sessegnon, Mitrovic. Subs (not used): Button, Norwood, Kebano, Fonte, Kamara.

BOOKED: Ream.

GOALS: R. Sessegnon (46), McDonald (56), Mitrovic (89).

REFEREE: Andre Marriner (Birmingham).