"It was incredibly tough and I was expecting a tough match today", Kyrgios said.
"I know that and there's no point trying to convince anyone otherwise".
"There is a constant tug-of-war between the competition within me wanting to win, win, win and the human in me wanting to live a normal life with my family away from the public glare".
But there was no doubting his commitment to the cause in the Belgian capital on Friday as he sent down 34 aces in a come-from-behind 6-3 3-6 6-7 (7-5) 6-1 6-2 win that silenced a partisan home crowd.
"This is what Davis Cup is about", said Serbia captain Nenad Zimonjic. Whoever was going to win that one was going to turn it all around.
In a wide-ranging piece he wrote for the newly launched Players Voice, Kyrgios offered up his opinion on Tomic's future and said "a lot has changed" since he was good friends with the 24-year-old. But in the fourth set, Lajovic broke early on and set up a match point at 5-3.
That's followed by French number one Jo-Wilfried Tsonga crossing swords with Davis Cup debutant Laslo Djere, the highest-rated Serbian at No.80 in the world.
Goffin won a tight baseline battle that lasted 3 and half hours against Millman, triumphing 6-7 (4), 6-4, 6-3, 7-6 (4) to extend his Davis Cup record to 14 wins from 15 matches. France captain Yannick Noah was critical of his own performance.
"I didn't play my best tennis but I served well on the big points and that is the best part of my game".
But one motivating thought I have is to earn enough money to build a centre for kids who are homeless, having problems at home or don't have the financial means to play sport. "I'll have to improve our communication for the next rubber".
After being knocked out of the US Open first round last month, he told reporters he was "not the smartest guy in the world" and tennis was all he knew.
Seeking their second final in three years, Belgium went ahead with Goffin, the world number 12, coming from a set down to beat Millman, ranked 185, 6-7 (4) 6-4 6-3 7-5. Kyrgios played a huge part in the tie, winning the 2nd rubber over John Isner in three sets, and the 4th rubber to close out the tie with a three-set win over Sam Querrey.