Embattled world champion Armitstead was given a Rio reprieve over three ‘failures’ to keep anti-doping officials informed of her whereabouts when the first was declared void by the Court of Abitration for Sport.
But Britain’s first medallist in London 2012, when she won silver on The Mall behind Marianne Vos, could only finish fifth in the 137-kilometre road race as Holland’s Anna van der Breggen won a dramatic gold.
Armitstead said: “I can’t feel sorry for myself. This is sport and that’s what it’s about.
“You open yourself up for judgement. I never gave up and for that I can be proud of myself.
“Obviously I’ve lost quite a lot of sleep and it’s been a hard time, but it’s not an excuse.
“Once I’ve got a number on my back I’m a totally different person and I’m focused and it didn’t enter my mind once in the race. I was totally focused on what I do best.
“It’s a deserving Olympic champion for sure.”
Holland’s Annemiek van Vleuten led with less than 11km to go, but crashed on the descent that had ended men’s race leader Vincenzo Nibali’s chances 24 hours earlier.
Initial reports on Twitter from the Dutch Cycling Federation said that Van Vleuten was “OK”.
The crash allowed Mara Abbott of the United States to take the lead, with Sweden’s Emma Johansson, Elisa Longo Borghini of Italy and Van der Breggen of Holland in pursuit.
Abbott had an advantage of almost 40 seconds as the descent flattened out, but was caught in the final 200m and denied a medal.
Van der Breggen took gold, Johnsson silver and Longo Borghini bronze.
Armitstead added: “It wasn’t entirely unexpected. I knew I was going to need a miracle to come away with the gold medal on this course. I came up short on the climb. That’s what I’ve been working hard on, but that’s sport.”
It was a compelling race, but Chris Boardman, 1992 Olympic champion and BBC commentator, thought the route was “dangerous”.
Hesaid: “I’m actually quite angry because I looked at the road furniture and thought nobody can crash here and get up. This was way past technical, this was dangerous.”
Armitstead, whose team-mates Emma Pooley and Nikki Harris did not finish, was cheered by a small throng of supporters waving Union Flags with “Team Armitstead” on them and a banner saying “Go Lizzie” .
The 27-year-old from Otley, West Yorkshire, had her sunglasses on her helmet and a steeliness about her eyes on her arrival at the start after a trying week.
Armitstead had been provisionally suspended by UK Anti-Doping on July 11 for three whereabouts ‘failures’.
CAS ruled in her favour, scrubbing the first ‘strike’ from her record, but her results will forever have an asterisk alongside them in the eyes of many who believe she should not have been in Rio at all and should instead be serving a two-year suspension.