"Got off to a really good start and I feel like a lot of things we have been working on, I was able to implement them," Anderson said in Brisbane.
"A little bit physically draining after my first match. It's always, as much as you work off the court, it's always a little bit different being in a match environment.
"But a really good day of recovery yesterday and my body felt really good being out there today."
The world's top players have assembled for the ATP Cup and are using the event to prepare for this month's Australian Open, which starts in Melbourne from January 20.
Marin Cilic, the US Open champion in 2014, followed up Saturday's win against Austrian Dennis Novak with a 7-6(8) 6-4 win over 20-year-old Kacper Zuk of Poland.
Cilic converted only one of 13 break point opportunities but his win in Sydney was enough to set up Croatia's second victory at the event after they blanked Austria 3-0.
"Today, if I have to pick some things that I need to do better, it's just converting break points. I had a lot of them," Cilic said.
"But otherwise, I felt that the level was quite good. I was being aggressive."
Japan also completed their second win as Yoshihito Nishioka and Go Soeda emerged victorious in their singles matches to seal the tie against Georgia in Perth.