The Argentina skipper received his marching orders on the stroke of half-time for a rash challenge on Tal Ben Haim after Nadir Belhadj had opened the scoring with a sizzling volley on 33 minutes.

Frederic Piquionne then sealed the three points for the hosts with a second goal eight minutes from time.

It means Rafael Benitez's men have now lost seven league matches this season and could fall further behind the top four if results go against them over the course of the weekend.

Prior to kick-off there had been concerns over whether the game would actually go ahead and the Liverpool players looked somewhat bemused as they took a pre-match wander on the frost covered turf.

For Jamie Carragher, a 600^th appearance meant another milestone and he was hoping to mark it in the same way he had celebrated his  100th, 200th, 300th, 400th and 500^th - with a clean sheet.

However, the prospects of that looked particularly dicey on six minutes when Michael Brown's lofted ball into the box saw Piquionne break the offside trap. The Frenchman looked odds on to score, but fortunately for Liverpool Pepe Reina was out to make a well-timed block.

In attack Fernando Torres was eyeing his 50^th league goal in red and it could have arrived on 10 minutes but Ben-Haim stole it off his toe just when it looked like our number 9 would dispatch Andrea Dossena's cross beyond Asmir Begovic from eight yards.

Next it was Dirk Kuyt's turn to cause havoc in the Pompey penalty area but the Dutchman missed his kick after Steven Gerrard had headed Torres' cross into his path.

The Spaniard was enjoying a lively opening and twice went close to making the breakthrough midway through the half. First he saw a sumptuous curler arc inches wide of Begovic's upright before coming within a millimetre of turning home Gerrard's angled cross on the stretch.

Earlier in the season a trip to the south coast had proved profitable for the first five Barclays Premier League teams to visit Fratton Park, and given Liverpool's dominance it looked like another away side would be going home with all three points again.

But since the appointment of Avram Grant, Pompey have looked a different proposition and as the half wore on they began to pose a greater threat.

Hassan Yebda was denied an opening goal when his flying volley struck Carragher in the face and after more good approach play, it was no surprise when they took the lead on 33 minutes.

The Reds failed to deal with a driven ball into the box and although Reina denied Kevin-Prince Boateng's rasping volley, Belhadj was on hand to crash home from a tight angle.

It was a frustrating setback for Benitez's side but they could have been level just six minutes later. Gerrard swung a sublime free-kick to the far post where Daniel Agger ghosted in unmarked, only to put his free header over the bar.

It would prove a crucial miss too, as Liverpool suffered a major blow on the stroke of half-time when Mascherano was sent off for a foul on Ben Haim. The Argentina midfielder appeared to injure himself in the challenge and after lengthy treatment referee Lee Mason gave him a straight red card.

There was no denying that it would be an uphill battle in the second period and in recognition of that fact, the travelling Kop gave a heart-warming rendition of 'You'll Never Walk Alone' as it got underway.

It seemed to do the trick early on as Liverpool dominated the play and Dossena tested Begovic with a deflected shot from distance. It was the Italian's last contribution as he was replaced by Yossi Benayoun just minutes later.

In their attempts to get back into the game, the 10-men were always going to leave space at the back and Portsmouth would have been two ahead on 56 minutes if Carragher hadn't produced one of his trademark blocks to deny Piquionne.

Liverpool needed a flash of inspiration and they almost got it on 66 minutes when Gerrard surged on to a loose ball and drove at the hosts' defence. Side-stepping his man, he fed Kuyt on the right edge of the area. The forward's cross was disappointing, but our number eight regained possession and hit a shot that took two deflections before being brilliantly saved by Begovic.

More of the same was needed if Benitez's men were to restore parity, but with the game stretched Pompey were just as dangerous on the counter. The impressive Jamie O'Hara sent a volley on the turn just off target while Piquionne headed wide with the goal at his mercy.

As time started to run out, Torres opted to go it alone and almost snatched an equaliser when his mazy run took him beyond five, only for a last-ditch tackle to deny him at the last.

An El Nino goal would have seen him become the fastest player in Liverpool's history to score 50 league goals, but it wasn't to be on this occasion, as Piquionne sealed victory when he turned Carragher and drilled home on 82 minutes.