Dan and Chong Wei exchanged jerseys and hugged each other following the match, after 16 years of being both rivals on court and friends off court, reports Xinhua.
As a seasoned veteran, Dan is the one who best understands Wei's efforts and wished him good luck.
"I hope he can have a good performance tomorrow in the final. As we become older, both of us have to train really really hard to stay at the level we are now," said the 32-year-old Chinese.
Chong Wei will face Dan's team-mate Chen Long, a two-time world champion, in the men's singles final after Long thrashed Denmark's Viktor Axelsen 21-14, 21-15 in 48 minutes at the Pavillion 4 of the Riocentro.
Super Dan won record two consecutive Olympic gold medals at the 2008 Beijing and 2012 London Olympic Games, twice beating the Malaysian in the finals to mount the top of the podium.
This time in Rio, history had seemed to repeat itself when Dan sailed to a first set win 21-15 with ease in the semi-finals.
However, Chong Wei fought back in the second and took the match to the decisive third set.
The two players went point for point until the 32-year-old Malaysian managed a 20-17 lead, but Dan saved three match points to level the score at 20-20.
The Malaysian eventually withstood the pressure by taking the final two points to claim the long-awaited victory.
"I never beat Lin Dan at the important world competitions such as Olympics and World Championships," Chong Wei said after winning the semi-final clash.
"When I finally won the match, I thanked God. It's destiny.
"I feel proud for both of us. We can still compete together with young shuttlers at the age of 33," added the two-time Olympic silver medallist Chong Wei.
This is our fourth Olympics. It's an honour to represent my country."
