Fred Evans's bid to become the first Welshman to win Olympic boxing gold ended when he ran into a better welterweight in Serik Sapiyev.
The Kazakh boxer was simply too good for the 21-year-old from Cardiff, winning the gold-medal contest 17-9.
But Evans's silver medal makes him the most successful Welsh Olympic boxer, beating Ralph Evans's bronze in 1972.
Evans reached the final with four victories, including a victory over world number one Taras Shelestyuk.
Fred Evans on winning silver
"No excuses, he was sharper and I did not stick to my plan correctly," said an exhausted Evans. "I am still young at 21, so I have done well and I am over the moon."
Sapiyev, a two-time world champion at light welterweight, stepped up to the 69kg division after the Beijing Olympics and won a bronze medal at the 2009 Worlds and a silver last year.
He was always going to be a handful. Quite how much of a handful became immediately apparent in the first round when the 28-year-old southpaw burst out of the blue corner and started throwing flurries of combinations behind his strong right jab.
Evans was being outworked and trailed 4-2 at the end of round one.
The second round followed the same pattern, with Sapiyev dictating the pace and Evans trying, but failing, to counter with big left-hand punches over the top of his opponent's jabs.
It was a fight too far for Evans. He had hard fights all the way through, particularly in the semi-final against the world number one. It was one hurdle too much for the kid from south Wales.
Trailing 10-5 going into the last round, Evans did his best to respond to the crowd's exhortations, but he looked ragged, allowing Sapiyev to stretch his lead to 17-9.
Amir Khan, the man whose Olympic display in Athens inspired Evans to pursue his boxing dream, said the Welshman might have let nerves get the better of him against the more experienced Sapiyev.
"Not sticking to the game plan and concentrating cost him the final," said Khan, the 2004 silver medallist. "But he has done so well, he has a very bright future in front of him.
"He should not be ashamed of anything. I want to give these boxers advice from my experiences of the professional game."
Kazakh boxers have now won this title for the third Games in succession. This is also the former Soviet state's seventh gold medal at London 2012.