England emerged comfortable 31-12 winners against Argentina at a subdued Twickenham, but another patchy performance in the QBE Internationals posed as many questions as answers.
Tries from Joe Launchbury, Billy Twelvetrees and Chris Ashton helped establish a 24-6 interval lead and when they appeared for the second half a landslide victory beckoned.
The energy drained from their game, however, as their previously dominant pack were met on equal terms by resurgent Argentina and their backline shuffled pointlessly across the pitch, bereft of ideas.
A late try from substitute Ben Morgan pulled them clear, ending a Pumas fightback founded on the place kicking of fly-half Nicolas Sanchez.
Owen Farrell finished with 11 points after landing a penalty and converting all four of England's tries as the team posted their ninth win in 10 matches and their sixth successive victory at Twickenham.
It is an admirable run of results, but this was not the warm-up head coach Stuart Lancaster was seeking ahead of New Zealand's visit next Saturday in the climax to the autumn.
Several of the players who were muted in the 20-13 victory over Australia were more conspicuous, inside centre Twelvetrees and scrum-half Lee Dickson among them, at least in the first half.
But even they faded alongside their team-mates as England lost their way alarmingly as the match deteriorated into a drab spectacle, spoiling memories of the early glut of tries.
Among those to hold their head high was hooker Dylan Hartley, who was superb throughout, carrying the fight to Argentina and deservedly finishing man of the match.
There was no lack of ambition from England, a fact apparent early on as once Farrell and Sanchez had exchanged penalties, the Saracens fly-half found touch instead of taking a shot at goal.
The bold move continued a promising spell as England's confidence grew and from the ensuing line-out they were held up over the line.
Referee Pascal Gauzere gave them a second stab at the whitewash, however, and this time once Hartley had found Courtney Lawes, they drove over with Launchbury touching down.
Argentina gained a foothold at the scrum, winning a penalty against David Wilson that long-range specialist Marcelo Bosch sent between the uprights with a gigantic kick.
Ashton harmed his chances of being retained against New Zealand after failing to complete a simple finish once a pass from full-back Mike Brown left him with only Lucas Gonzalez Amorosino to beat.
But England would not be thwarted in the 22nd minute and Ashton played a role, scooping up a loose ball during a backs move and feeding Twelvetrees.
Twelvetrees had Brown in space outside him but used his strength to power over, breaking three tackles, and Farrell converted.
There was no respite for Argentina as ruthless England ran in a third try with Ashton the scorer.
Chris Robshaw and Hartley, who repeatedly carried the ball into the heart of the Pumas defence, made yards and in an instant the ball was switched right with Farrell sending Ashton over.
Loosehead prop Alex Corbisiero appeared for the second half, replacing Joe Marler, but it was Argentina who started brighter after the interval.
Even with British and Irish Lions hero Corbisiero on the pitch their scrum remained on top, winning a penalty that Sanchez dispatched.
England needed to meet the Pumas' revival head on and they did just that with Robshaw, Farrell and Courtney Lawes flattening opponents with big tackles.
When they eventually took possession, the accuracy that decorated their play in the first half had vanished with Twelvetrees among those no longer so composed on the ball.
The next score was supplied by Sanchez, cutting the deficit to 24-12 as England continued to lose their way in the third quarter.
Argentina were now the dominant force as England continued to stumble aimlessly through the second half.
Sanchez missed a penalty, but the Pumas remained in possession with Benjamin Macome almost wriggling through a gap.
They were caught off guard with four minutes to go, however, as substitute Morgan capitalised on some poor tackling after a line-out to storm over.