Javier Mascherano and Jamie Caragher were the only recognised names in an otherwise second string Liverpool line-up.
In the early part the Whites dominated and had an early goal disallowed as Luciano Becchio was deemed offside when paring up with Jermaine Beckford.
After that, Leeds continued to press and were unfortunate to be on the losing end with players such as Robert Snodgrass and Patrick Kisnorbo putting in outstanding performances in front of a sell-out crowd.
Ngog, who played with credit on the night, broke Leeds' hearts just after the hour mark when picking up on a timely ball from Mascherano to turn and slot home from close range.
Steven Gerrard and Glen Johnson made brief appearances towards the end of the match as the Reds saw out a narrow win to secure passage through to the last 16 with a virtually second-string squad.
Atmosphere
It was Liverpool's first visit to Leeds since their hosts were relegated! from the top flight in 2004 but the atmosphere generated by the 38,168 crowd rekindled memories of a once intense rivalry.
Leeds, looking upwards again after an unbeaten start to the season, played like they had a point to prove against a Liverpool side showing nine changes.
Jamie Carragher, who took over the captaincy, and Javier Mascherano were the only survivors from the Reds side which won at West Ham last weekend.
Manager Rafael Benitez, however, had big guns Steven Gerrard, Fernando Torres and Glen Johnson on the bench in case not all went according to plan.
It seemed a sensible insurance policy as for large parts Leeds, with Robert Snodgrass a constant danger on the right, exploited the unfamiliarity in the Liverpool ranks.
There was a huge roar inside the opening minutes when Beckford went down in the area but referee Alan Wiley gave nothing.
Leeds were keen to attack and gave warning when Snodgrass ! broke free, although his cross was easily claimed by Liverpool! keeper Diego Cavalieri.
Ngog, starting up front alone, then got into the game with a couple of breaks but saw a long-range shot after a neat turn blocked.
Leeds then missed a glorious chance to take the lead when Snodgrass delivered a perfect cross but Michael Doyle headed wide from about eight yards.
The Yorkshire side had the ball in the net after 11 minutes when Beckford turned in Michalik's goalbound header from close range but Wiley ruled the striker offside.
Luciano Becchio also tried his luck for Leeds but curled wide from 20 yards.
Ryan Babel, hoping to stake a claim for a regular place, created Liverpool's first serious chance after a run from deep but Shane Higgs dealt comfortably with his tame shot.
Snodgrass caused further alarm in the Liverpool defence with another deep cross from a clever Beckford flick but Cavalieri just did enough to frustrate Becchio.
Albert Riera should have given Liverpo! ol the lead, against the run of play, on the stroke of half-time after meeting a Fabio Aurelio free-kick but Higgs saved his firm header.
The outstanding Snodgrass weaved his way into the Liverpool box soon after the restart but the visitors eventually managed to crowd him out.
Leeds continued to look the most likely side but Liverpool youngster Jay Spearing got a shooting chance from a Riera lay-off, only to fire well over.
Beckford then raced on to a long bouncing ball but scuffed his shot when any firm contact might have beaten Cavalieri.
The Leeds striker had another gilt-edged opportunity when Bradley Johnson crossed from the byline after 63 minutes but, after turning brilliantly, he sent his shot over.
Leeds paid the price as Liverpool went ahead two minutes later.
Mascherano mis-hit a shot from the edge of the area but Ngog reacted quickly and seized on the ball to tuck past Higgs.
Leeds tri! ed to respond as Johnson controlled a Michalik long ball outsi! de the a rea but shot straight at Cavalieri.
Liverpool brought on Johnson and Gerrard in an attempt to see out the game but Leeds continued to push.
Johnson needed to intervene to head back to Cavalieri as Liverpool struggled to clear another Leeds attack.
Liverpool did break out again with Babel winning a free-kick on the edge of the area but Aurelio's shot was deflected wide.
Gerrard almost made doubly sure of victory as time ran down but fired into the side-netting and then straight at Higgs after powerful runs.
Here we have the news that we all pretty much pretty much have surmised; thus, now it has come from Orioles' COO Andy MachPhail himself.
