Liverpool 1 Portsmouth 0
In a game of few clear-cut chances the Reds dominated possession but struggled to score against a well-organised Pompey side that was 14 minutes from taking a point from the league leaders.
Liverpool started the brighter of the two sides and for the first 20 minutes looked like they were playing a 4-2-4 formation with Dirk Kuyt and Gerrard leading the line with Jermaine Pennant and Ryan Babel bombing down the wings.
It was Kuyt who had the opening chance within the first two minutes when a driven corner passed through a crowded Portsmouth box straight to the Dutch forward but he blasted high over a grateful David James' bar.
The home side kept up the pressure and it was Kuyt again who let rip from the edge of the box on nine minutes that brought the best out of the Pompey shot-stopper whose strong hand down to his right pushed the ball onto the post.
The lead should have been taken on 11 minutes when an inswinging Gerrard corner found Lucas unmarked but the midfielder rose unchallenged and powered the ball over the upright.
Hoping to kick-start his managerial role with a win, Portsmouth boss Tony Adams decided to play former Red Peter Crouch as a lone striker and, despite winning every long ball pumped up front, the lone forward provided little threat for his side.
Against the run of play the visitors should have taken the lead after a Sean Davis cross found Papa Bouba Diop in the six-yard box with only Pepe Reina to beat but his header was directed straight into the arms of the keeper.
Liverpool were restricted to long-range efforts and a 30-yard drive from Jamie Carragher and a similar effort from Gerrard just before the break tested James.
The second half was a much more open game with both sides creating chances but it was Liverpool who should have taken the lead after Gerrard drilled the ball across the face of goal only for Kuyt to waste the chance.
It was the Liverpool captain who split the defence just before the hour mark to feed Kuyt who cleverly laid the ball into the path of an onrushing Lucas inside the box but a last-gasp lunge from Sylvain Distin blocked the shot and kept the scores level.
The subsequent corner was then headed against the outside of the post by Sami Hyypia who rose highest to meet the looping cross.
Liverpool must have thought they would never put the ball in the net as Distin again saved his side from going a goal behind after substitute Yossi Benayoun was clean through on goal but the towering centre-half managed to throw his long legs in front of the shot.
The England number one almost played his side into trouble on 74 minutes after a quick throw out to Lassana Diarra put the midfielder under instant pressure and his mis-control gifted the ball to Arbeloa who drilled a thunderous effort goalbound.
However, the keeper was well positioned to palm the ball wide for a corner.
With only 14 minutes left on the clock a moment of madness from Bouba Diop gave the game away as he needlessly handled the ball in the area from the corner.
After losing his man Bouba Diop struggled to make up the lost ground and with two fists raised he punched the ball off the head of Kuyt giving the referee no option but to point to the spot.
Despite guessing the right way, James could do nothing to keep out Gerrard's low thunderbolt into the corner of the net.
The visitors could have squared the match on 83 minutes after a high cross from Nadir Belhadj but John Utaka couldn't stretch his neck any further and missed the ball from four yards out.