Phillips now readies himself to race the annual Honda New Zealand Motocross Grand Prix at Woodville next weekend and the four-round national champs that follow soon afterwards.
The opening round of the nationals will be on February 8 on the same hilly circuit that he conquered on Sunday.
"It wasn't easy today," Phillips confessed, eventually winning the class by just one point from Atiamuri's Hadleigh Knight.
"I feel just happy to have finished that last race. It was hard to see in the blinding dust and it was quite dangerous.
"I had to keep Hadleigh in sight and be aware of where he was on the track. I didn't have to beat him in the final race, but I knew I needed to be close, maybe just one place behind him."
In the end, Phillips' scorecard was 1-2-2 for the day, enough to edge out Knight, who finished 4-1-1.
"This is a great build-up for me for the nationals," Phillips said. "I've now had a few wins on the track and finished runner-up at the Valley Motocross Champs [near Morrinsville] last weekend, so I've won a permanent spot on the team. It has been a few good weeks for me.
"That's not too bad for a guy who is supposed to be retired from the sport."
Meanwhile, Mount Maunganui's Rhys Carter won the MX1 class ahead of Queenstown's Scott Columb on Sunday, with Phillips' younger brother and Honda teammate John Phillips third overall.
Auckland's Kurtis Lilly won the senior 125cc class ahead of Ngatea's Ben Broad and Auckland's Sean O'Connor.