With no sting in their bowling attack, Tech rotated nine players through the strike.
While United captain Max Carroll fell early, Lance continued on with his positive stroke play, with Viljoen coming in to join him and they carried their team all the way to the target, inside of 25 overs.
Tech let professional Viljoen know they weren't happy with the time he would take to set between deliveries, yet patience was obviously a virtue as the international scored 73 off 54 balls, including six boundaries.
The result makes it likely the title will be decided between United and the season's other dominant side, Bayer Marist, who routed Wanganui Collegiate to the tune of 224 runs.
The schoolboy's First XI have not been able to offer much at senior club level in the new year, and their bowlers took a pounding as Marist raced to a whopping 394.
Craig Thorpe had the innings of the summer so far with 160, while Todd Inness and captain Mark Fraser reached the 60s.
Charlie Greatbatch, the son of former Black Cap Mark, stood out like a beacon amongst the Collegiate bowlers with a somewhat respectable 2-49.
In reply, the school team was all out for 170, with Nick O'Leary's score in the 30s being the best individual contribution.
As Marist won the Premier League and knockout competition, while United wrapped up the Twenty20 title, the 50-over crown will go a long way to deciding which club had ascendancy in 2014-15.
Both will suffer from withdrawals as some of Marist's key players return to university, while several United men have commitments to attend weddings in coming weeks, although the acquisition of Viljoen will offset that.