KUALA LUMPUR: Shuttler Lee Zii Jia put the nation's interest above his friendship with Denmark's Anders Antonsen in the Olympic quarter-finals this morning in Paris.
Zii Jia upset the world No. 3 Viking to march into the men's singles semi-finals.
The duo have clashed on eight previous occasions, with Antonsen holding a 5-3 advantage over world No. 7 Zii Jia.
But Zii Jia must have felt that he had the edge, entering the court this morning at the Porte de la Chapelle Arena.
For in their most recent meeting, Zii Jia defeated Antonsen in the Malaysia Masters quarter-finals in May. He went on to finish runner-up to Antonsen's compatriot Viktor Axelsen.
The 26-year-old Malaysian carried that form into Paris and overpowered Antonsen 21-17, 21-15 in 53 minutes.
"I'm quite happy with my performance, I was surprised by how calm I was today," Zii Jia told BWF.
"Anders and I have played each other a few times. Even though we are friends, we are clear with each other that on the court, we are enemies.
"We represent our country with honour and give our best no matter what happens," the Kedahan added.
Zii Jia was in control throughout the match, and he was aided by an error-strewn performance by Antonsen.
"I can feel Antonsen's desire to win, maybe that was one of the reasons he made so many unforced errors.
"This is the Olympics. When we step onto the court, we all want to win and it's up to who can be calm and manage all kinds of situations, especially the pressure," said Zii Jia.
In the semi-final tomorrow, Zii Jia will face reigning world champion Kunlavut Vitidsarn of Thailand who knocked top seed Shi Yu Qi of China out of the Olympics.
Zii Jia has a 4-4 head-to-head record against Kunlavut, with the Thai winning their last encounter, at the quarter-finals of the Indonesia Open in June.
"Kunlavut is a world champion, and my head-to-head against him is not very good.
"He is in his best form and he just dumped out the top seed. He looks like he is in good condition and has a lot of confidence, so yeah we will see what happens," said Zii Jia.
Prior to the Paris Olympics, Zii Jia had headed to Singapore to spar with Kunlavut and former world champion Loh Kean Yew.