China's Zhang Nan (L) and Zhao Yunlei pose with their gold medals
China won the opening badminton title of the London Games as Zhang Nan and Zhao Yunlei became the first boyfriend and girlfriend duo to win Olympic gold medals together.
Zhang and Zhao, who also won the world mixed doubles title in the same Wembley Arena venue a year ago, took the Olympic gold medal with a 21-11, 21-17 win over their second-seeded compatriots Xu Chen and Ma Jin.
Their success raised the possibility of the world's most powerful badminton nation winning all five Olympic titles at a single Games for the first time.
China are already certain of the women's singles title, and have surviving players in all the other three events.
At the end of the match Zhang threw his golden-coloured shoes into the crowd in celebration.
In the past, Chinese athletes have sometimes been discouraged from dating team-mates, but badminton head coach Li Yongbo has adopted a more liberal attitude, both to Zhang and Zhao and in the past to other players.
Most notably he allowed a relationship between Olympic men's singles champion Lin Dan, and the former women's singles world champion Xie Xinfang, who are now married.
This is perhaps unsurprising since Li apparently met his wife, the rhythmic gymnast Xie Ying, at a training venue in 1983.
Zhang and Zhao's relationship apparently came to light when they hugged and kissed after winning the Japan Super Series title two years ago.
Indonesia's Susi Susanti and Allan Busi Kusuma, now a married couple, also won Olympic gold medals on finals day in Barcelona in 1992, but did so in their respective singles events.
Even though there were some sensational rallies of attack, defence and counter-attack which often made a fine spectacle, there was only ever much doubt about the outcome of Friday's showpiece match until just before the end.
Then, after establishing an eight-point second game lead, the eventual champions relaxed, allowing a nervous-looking Xu Chen to launch some significant blows and claw the deficit back to two points at 17-19.
But thee gold medallists finished off the match when Zhao once again established a good net position, enabling Zhang to batter some heavy blows from the back and penetrate their opponents' defence.
"We have been training very hard and I think this gold medal will just be a beginning for our career," said Zhao, which sounded almost as though she had the 2016 Rio Games in her thoughts already.
However when asked if the gold medal became more important because of the negative publicity surrounding the Chinese team following the expulsion of women's double duo Yu Tang and Wang Xiaoli as part of the match fixing scandal earlier in the tournament, the new champions were more guarded.
"Everyone has trained very hard to put on their best performance," said Zhao.
"I am not familiar with what happened in the past few days," added Zhang.
Earlier China became sure of at least two gold medals when Wang Yihuan, the top-seeded world number one beat Saina Nehwal, the Commonwealth champion from India, to reach the final of the women's singles, where she plays her compatriot Li Xuerui, the All-England Open champion.
China also have two semi-finalists in the men's singles and the top seeds in the men's doubles, with Zhao Yunlei in with a chance of a second gold medal, having also reached the final of the women's doubles with Tian Qing.