At one stage David Murdoch’s British quartet had trailed 5-1 after an impressive opening half from the Danes.
However, the game turned in the sixth end when British skip David Murdoch clinched a three-pointer to close the gap to one. Murdoch then turned the screw to level at 6-6, before sealing a dramatic win.
“An incredible game,” was how the British skip described it. “I've never come out from a game of curling with an adrenalin rush like that for a long time.”
Fellow frontrunners Sweden dramatically leapfrogged China in the morning session, ending their opponents’ 100 per cent record with a tense 6-5 victory.
The world champions were two points down after two ends, but fought back to lead 5-4 going into the final end.
China missed a golden chance to win before Sweden skip Niklas Edin made a double take out with his last stone, to tie the scores at 5-5 in the tenth, and set up an extra end victory for the Scandinavians.
“We played a pretty good game, but they didn't miss anything for the first five or six ends,” said a relieved Edin. “We played a bit safe but had a perfect second half.”
China bounced back in the evening session with a 7-5 victory over Norway.
The game could have gone either way until China's skip Rui Liu pulled off an audacious two-pointer in the sixth end to give his team a 5-3 led from which the Norwegians never.
Afterwards, Liu played tribute to the losers. “Team Norway is really strong - they won the silver medal in Vancouver and we’ve learned a lot from them” he said.
It was not Norway’s day, as earlier they went down to a heavy 10-4 defeat against defending champions Canada, in a re-run of the Vancouver 2010 final.
The game was gridlocked at 3-3 early on, but Canada then pulled clear with four points in the seventh and three more in the eighth to force the concession.
Skip Brad Jacobs admitted that patience had been key: “The beginning of the game was a little frustrating, but we just stuck with it,” he said. “Norway are a great team, so that was a huge win.”
There was a second win of the week for USA, who recorded a welcome 8-5 victory over winless Germany.
The match turned during the third end, when US skip John Shuster removed a hidden German stone with a delicate shot to set up a score of four points and a 4-1 lead.
Another four-point haul in the seventh end was enough to end German hopes of a comeback.
However, the Germans did finally record their first win of Sochi 2014 in the evening when they edged an 8-7 nail-biter against Switzerland.
Germany made the first break-through with a single-point steal in the seventh end for a 6-4 lead, but the Swiss responded straightway, scoring two points in the eighth end to level the game at 6-6.
In the ninth end Germany's Felix Schultz scored two points for an 8-6 lead, for which the Swiss had no adequate riposte.
“Our first win! We’re happy now,” said German skip John Jahr. “It was a tough game, a good game, but we needed this one!”
Noise levels at the Ice Cube were ramped up as Russia faced USA in the evening’s other match.
The hosts gave local fans something to cheer as they scored two points in the second end followed by a steal in the third to open up an early 3-0 lead.
But the US quartet fought back strongly to level at 3-3, before the teams traded points to reach 5-5 after six ends. Russian skip Andrey Drozdov then clinched a last end winner with his final stone to make it 7-6.
“If we win all of our remaining games you never know, something might happen,” said a delighted Drozdev.
Men’s standings after 8 sessions:
1. China 5-1
1. Great Britain 5-1
1. Sweden 5-1
4. Canada 4-2
5. Norway 3-3
6. Denmark 2-4
6. Russia 2-4
6. USA 2-4
9. Germany 1-5
9. Switzerland 1-5