SINGAPORE - For 50.39 seconds, he kept his gaze fixed on the TV. Hands covering his mouth, there was not a word from him, even as the others around him jumped in excitement.
When it was all over, he sank into his seat. His face finally broke into a wide grin, and tears of joy welled up.
His son Joseph Schooling has just made history by winning Singapore's first Olympic gold.
Visibly emotional, Mr Colin Schooling, who was watching the race at the home of his son's close friend and fellow national swimmer Teo Zhen Ren, said: "Thank you everybody."
The 68-year-old did not travel to Rio with his wife, May, 61, because he was not feeling well.
His first words to his son: "I love you. Son, you have done the nation very proud."
Before the race, he had encouraged his son: "I want you to stun the world."
May Schooling had also told The Straits Times: "If all goes well, Singapore will rejoice with us."