Then in this morning's race McNee won, banking a valuable 75 points - but Alexander was a close second, effectively putting the championship out of reach. The leading three - McNee, Alexander and Blewett - had formed a high speed 'draft' around the circuit, with all three covered by less than a second at race end.
The 15-lap afternoon race sealed Alexander's championship title, though not without startline drama after he selected third gear instead of first for the race start and was swamped by the field, ending up sixth at the end of lap one.
A determined fight back ensured, Alexander passing each driver cleanly in turn until he was second behind McNee. He then chased the leader down, his car improving lap by lap as it reached optimum race weight and the tyres were put to work.
"I was much faster through turns 2 and 3 and though the car was slower going into the final right hander I was getting great drive there for the run up to the start-finish. Lap after lap I was closer and closer to Jamie and then I had him," Alexander said afterward.
The pair were side by side for most of the lap as each fought to take and hold the lead in a thrilling duel. Eventually, Alexander went side by side into the hairpin and stayed with McNee down the next straight and into the final corner of the lap. Alexander's car had the advantageous inside line into the corner and the two cars made contact. McNee found himself spinning off the track, Alexander and the leading bunch disappearing up the hill.
Ashley Blewett had a momentary peep at the lead, but tucked in behind Alexander to chase him to the finish. Callum Quin was a strong-finishing third, while McNee had come back from P6 to be fourth.
But the win - and the championship - belonged to a delighted and excited Tom Alexander.
"I've wanted to win the championship since we first heard about it. This is amazing," he said afterward.
Alexander, 20, is a protégé of experienced racer Kenny Smith, who has shaped the careers of many aspiring young Kiwi race drivers. He is hoping to raise funds for a next step into New Zealand's premier single-seater championship, the Toyota Racing Series.