Olympics pole vault: Jennifer Suhr wins with Yelena Isinbayeva third
Jennifer Suhr of the United States edged a tight women's pole vault final at London 2012 to improve on her silver medal from the Beijing Olympics.
"I am really disappointed, but to come top eight in my first Olympic final is pretty good," Bleasdale said.
"I am just heartbroken with how it went. I am only 20 and I feel like I could have performed well this year."
The rain-affected final came down to a straight contest between the top pair, with neither able to vault beyond 4.80m. A failed attempt at her opening height of 4.45m by Silva saw her ultimately pushed into second place.
The result meant Russia's Isinbayeva failed in her bid to become the first woman in track and field history to win the same individual event in three straight Olympics.
Bleasdale's challenge got off to an uncertain start as she twice failed to make her opening 4.45m mark. The Wigan athlete, who wrapped herself in a Union flag between attempts, then recovered to progress to the relief of the partisan crowd in the Olympic Stadium.
Her run was not to last though and she went out at a height 16cm below her outdoor personal best to finish sixth. Fellow Briton Kate Dennison had earlier dropped out after injuring herself in the qualifying round.
Bleasdale's disappointment was tempered when her boyfriend proposed to her after the event.
She tweeted: "6th in the Olympics and @bradshaaaw proposes to me :) epic day!!!"
Her boyfriend Paul Bradshaw wrote on Twitter: "I have just proposed to @HollyBleasdale and she said yes!!!!! Best day ever!"