To ship a sloppy stoppage-time equaliser was apt; this was a wholly inadequate display to warrant local howls of frustration at the end.
If the occasion had called for the red part of Liverpool to exorcise a first derby defeat in five years, this merely prolonged the agony. Sluggish and mediocre before the interval, Liverpool's belated resurgence was checked at the last by a horribly familiar defensive error, with Jerzy Dudek this week's culprit.
Liverpool languish six points from fourth place this morning, let alone 15 from the top, with their long-held game in hand spent. "It's a bad situation but it's not the worst," offered Rafael Benítez. Yet for all that Portsmouth were resilient until breached by Gerrard's blistering shot 20 minutes from the end, he knew this was a win frittered away.
Portsmouth were struggling to muster much of a pursuit of parity when, two minutes into time added on, the substitute Matthew Taylor flung over a cross from the left which veered alarmingly at the goal. Dudek, poorly positioned, reacted late and could only palm up rather than away for Lomana LuaLua, attacking the loose ball, to leap above the flummoxed Sami Hyypia and nod into the empty net.
Benítez had recalled Dudek for his first Premiership start since September, with Chris Kirkland having succumbed to a lower-back injury, though the manager steadfastly refused to blame the Pole. "It was frustrating, but Jerzy was waiting for a cross which is what Taylor tried to do," he said. "It was a lucky goal and a difficult ball for the goalkeeper to deal with, but we missed so many chances and that is what cost us."
That much was true only in the second half, though Jamie Ashdown at the other end proved far less obliging. The former Reading goalkeeper denied Dietmar Hamann unbelievably from point-blank range and Harry Kewell, twice, from distance as he attempted to claim his side's first point at Anfield in 44 years. Yet those heroics seemed fruitless when Patrik Berger clattered Xabi Alonso 27 yards out and Gerrard, charging on to Hamann's touch, fired Liverpool ahead.
Not that they deserved their advantage. This had been a woefully lethargic display for too long, as if any remaining optimism had been drained by Saturday's defeat across Stanley Park. With such a lack of enthusiasm on the pitch, it was no wonder that those off it - their lowest league gate of the season - could raise little more than an exasperated murmur. Uninspired and predictable, the game had stagnated with little other than Hamann's early miss after Antonio Nuñez had flicked on Gerrard's corner to excite.
Portsmouth should have capitalised. They were largely content in defence but perked up appreciably whenever LuaLua burst on to possession. Ricardo Fuller slid the Congolese free midway through the opening period with LuaLua's curled attempt flicking off a defender and wide of the far post. He repeated the trick when Liverpool's nerves were jangling just before the interval, with Dudek's comical save from a horribly scuffed attempt a grim sign of things to come.
As it is, Portsmouth remain unbeaten in four games under the makeshift managerial team of Valimir Zajec and Joe Jordan, their travelling supporters still spitting "Judas" at the departed Harry Redknapp from the Anfield Road End.
Jordan seems in no particular hurry to take over the job. "I'm quite happy coaching the players and the team," he said. "That's what Harry wanted me to do, but I'm involved a little bit more now and, while I'm enjoying the extra responsibility, we'll see what happens."
He cut a forlorn figure as Gerrard's goal ricocheted in off the angle of post and bar, relief sweeping around the stadium, but the locals should have known better. It is nine games since Liverpool last kept a clean sheet and, even against opponents who had barely mustered a shot after the interval, they contrived to throw away their advantage yet again.
"It was a satisfying night," added Jordan. For Benítez and his captain, it was anything but.