Heather Watson and her doubles partner fall foul of the third seeded Italian duo.
Watson and Boulter had cruised through the earlier Olympic matches at Roland Garros, despite the odds being against them.
They beat the Germans Angelique Kerber and Laura Siegemund in straight sets, 6-2 6-3, on Tuesday, 30 July.
They reinforced their dominance with another straight sets victory over the sixth seeded Brazilian duo of Beatrice Maia and Luisa Stefani, winning 6-3 6-4, on 31 July.
But the third seeded Italians, Sara Errani and Jasmine Paolini, undid this progress in little over an hour, winning 6-3, 6-1.
Yesterday marked the end of an era for Andy Murray.
The two-time Olympic singles champion lost alongside Dan Evans in the quarter-finals in Paris.
There were tears as he was given a huge send-off by the crowd at Roland Garros.
User pays when Guernsey roads have to close
Channel Islander abandons Bordeaux as the flames 'arrive at the city's gates'
Annual Guernsey Scarecrow Festival set to raise thousands for charity
Channel Islands face 'physical' Poland test
Baby born on Guernsey's Marine Ambulance
New interim leader for Guernsey's healthcare system
Guernsey's reservoir levels falling after prolonged dry spell
Guernsey's Commonwealth flag carrier in early Games win
