Buchanan, 17, showed all his class for the Yamaha Racing Development team in the opening round of the New Zealand Superbike Championship in Taupo at the weekend.
The teenaged gun, who recently returned from a third season competing in Europe, won all three Supersport 600 races and added a lap record for good measure.
Despite not feeling at one with his Yamaha YZF-R6 in the practice sessions, when it came to qualifying on pole, he was full steam ahead.
"Race one, we didn’t have the best tyre strategy on old tyres when we should’ve been on new tyres but somehow we managed to win that race and set a new lap record of 1min 29.334sec," Buchanan said.
He won the second race when the leader crashed out and he was in the right position to capitalise on this misfortune.
"Race three was definitely the highlight where we were the only bike on wet tyres in the whole field and somehow, we managed to beat all the guys on slicks.
"Despite them passing me, I had to be aggressive and pass them straight back, or it would be the race over."
Buchanan said having the No1 plate on his motorcycle gave him the confidence to ride more "elbows out" compared with last season.
He also appreciated the tight racing and the top level of competition provided by fellow New Zealand international Shane Richardson, who finished second overall for the opening round.
Yamaha Motor New Zealand motorsport manager Josh Coppins described Buchanan’s weekend as "probably one of his best rides he has had with us".
"Cormac has been on a completely different bike all year in Europe and has had limited testing with us before the event," Coppins said.
"We had challenging conditions with changing weather, new tyres and wet and dry tracks. He managed the races so well.
"Everything was stacked against him but in racing terms he really had the top two inches. That was a comment his team manager Steve Lloyd made, and I couldn’t agree more."
Round two of the New Zealand Superbike Championship is at Manfeild this weekend.