England triumphed in their final workout before next month's Argentina tour -- but not before the Barbarians gave them a thorough examination at Twickenham.
And the 28-14 victory was achieved at a possible cost, with Argentina-bound squad members Alex Lozowski and Sam Underhill both suffering first-half injuries that could threaten their tour participation.
They appeared to suffer shoulder trouble serious enough to force them out of the action, giving England head coach Eddie Jones cause for concern ahead of next weekend's departure for South America.
Saracens pair Nathan Earle and Nick Isiekwe scored tries -- as did scrum-half Danny Care -- for an England side containing eight uncapped players, but the rest of their points came from fly-half George Ford, who kicked three penalties and two conversions.
The Barbarians replied through touchdowns by wing Adam Ashley-Cooper and replacement lock Joe Tekori -- fly-half Ian Madigan added two conversions -- and they caused England plenty of trouble, potentially considerably more than Jones would have wanted or expected.
The Barbarians announced their attacking intent within four minutes when Fiji international wing Timoci Nagusa ran from behind his own line, breaking a number of tackles before delivering a one-handed offload to scrum-half Kahn Fotuali'i, and it took Chris Robshaw's tackle to halt a stunning move.
England, though, remained under pressure, and centre Yann David ran straight through Underhill's attempted tackle as the home side struggled to cope with Barbarian pace and panache.
And they had a major let-off after just six minutes, with Nagusa again bursting clear, but the Baa-baas' England international full-back Alex Goode narrowly failed to gather with the line at his mercy.
England could not get going, and there were further problems midway through the opening quarter when Lozowski went off after appearing to suffer a shoulder injury, with Sale's Mike Haley replacing him.
But totally against the run of play, England scored, with Earle involved twice in a move that was sparked by his fellow wing Jonny May and ended with Earle touching down following centre Sam James' defence-splitting pass.
Ford added the conversion, and England led 7-0 despite being under the pump in defence. And England extended their lead 10 minutes before the break when Barbarians replacement Robbie Fruean was penalised for a late off-the-ball tackle on Mike Brown, and Ford kicked the resulting penalty.
Brown went off for a head injury assessment as a result, being replaced by scrum-half Richard Wigglesworth, who made his appearance due to being England's second and final back replacement on the bench.
The reshuffle meant that Wigglesworth went to scrum-half, Danny Care moved to the wing, Mike Haley lined up at full-back and Earle featured briefly in the centre before Brown rejoined the action.
Wigglesworth's main contribution during his brief stint on the field was to inflict a late ankle-tap tackle on Goode, which cost England a threatening attacking position, and then fresh injury woe followed as Underhill departed, with Sale's Tom Curry replacing him.
A second Ford penalty made it 13-0, with England clear at the interval despite conceding considerable second-best in terms of territory and possession.
But the Barbarians finally made things count, scoring an opening try after a slick attack ended with Goode sending an unmarked Ashley-Cooper over, and Madigan converted from the touchline.
It was another wake-up call for England, yet Ford completed his penalty hat-trick shortly afterwards and regained a degree of control on the scoreboard, nine points ahead.
The Barbarians had a try disallowed after 50 minutes, referee Andrew Brace debatably ruling out Jeremy Thrush's close-range effort following a knock-on during impressive approach work, and England's advantage remained intact.
Barbarians prop Mikheil Nariashvili was yellow-card for a scrummaging infringement as the game continued to groan along, before Isiekwe scored when he finished off a slick move that also involved May, Ford and Isiekwe's second-row partner Charlie Ewels, and England were hone and dry, with Care's last-gasp effort taking them further clear.