Mihailo Ivanovic's first-half goal and Millwall's admirable defensive performance was enough to beat Portsmouth and keep a clean sheet at Fratton Park.

Ivanovic scored the game's only goal just before half-time with a delightful chipped finish over the onrushing Nicolas Schmid.

It was Ivanovic's fourth goal of the season and moves the Lions up two places to 14th, while Portsmouth remain in 21st and two points above the Championship relegation zone.

Tuesday night's game was a rescheduled match following a postponement in November due to a floodlight failure at Fratton Park.

Portsmouth had won six and drawn one of their previous seven home games, but Alex Neil's side brought that impressive unbeaten run to an end.

It was a competitive opening 15 minutes, but the one big chance fell to the away side.

Millwall countered at pace and a pass was put on a plate for Ra'ees Bangura-Williams in space at the back post.

But he let the ball run across his body and side-footed his shot wide of the right-hand post to the dismay of the Lions fans behind the goal.

Portsmouth responded by carving out a decent chance of their own - Josh Murphy's low cross from the left found Colby Bishop but the striker could not get enough contact on his effort.

The ball rebounded to the onrushing Matt Ritchie but his powerful shot was well blocked by Joe Bryan.

Millwall then took the lead just before half-time with a devastating attacking move, Bangura-Williams slotting a beautiful pass in behind the Pompey defence which Ivanovic latched on to.

As Schmid rushed out to stop him, the Serbia international calmly chipped the ball over the keeper and ran off in celebration as it trickled over the line, with the away fans celebrating jubilantly as the ball nestled in the back of the net.

Portsmouth started the second period with intent and pushed the Millwall defence back deeper into their half.

Murphy caused trouble with his pace and trickery down the left-hand side and created a number of opportunities, with Ritchie heading narrowly wide from one dangerous cross.

Pompey dominated the second half but Millwall's most notable chance in the second period came from Aaron Connolly who curled an effort with his right foot just wide of the post from the edge of the area.

The hosts pushed in the final moments that remained, launching long throws into the box but were unable to find a breakthrough - the best chance a header from Bishop that flew just over the crossbar.

Portsmouth boss John Mousinho said:

"I think it's frustrating from several points of view. First off, we didn't put the ball in the back of the net after some really good opportunities.

"Then we went a goal down to a side who know how to defend a 1-0 lead really well, which was disappointing because we were in control of the game.

"We should've stopped their goal, we had the ball and were driving towards the box, and then they went and scored.

"After that our keeper didn't have much to do, but we didn't have enough to get back into the game."

Millwall manager Alex Neil told BBC Radio London:

"If we are prepared properly, if the lads put everything into the game, and if we have those moments of quality then our players are certainly capable.

"Everyone knows we are light on players at the moment, but the squad available has been sensational to churn out these last few results.

"The goal was something we spoke about, so it was entirely by design. But the easy bit is planning the tactics, the hard bit is executing it, and the boys have been brilliant.

"My job is to make sure the players know what to do, and then to let them go and play."