Jordan Cohen and Cole Brasting each scored a brace of goals for Wanganui, while Tyler Nicoll-Hylton and Lane Madams chipped in with another one apiece yesterday.
Spence conceded the competition would get progressively stronger as the tournament progressed, but he had high hopes his boys could achieve their goal of finishing at least in the top four.
"We finished fifth overall in Christchurch last year, but I really do think we have a serious chance of bettering that and even winning the tournament. The boys are really confident and deserve to be," Spence said.
Wanganui meet Waikato, who finished second in Pool D, this afternoon and Spence believes they are "very beatable".
"If the boys play the way they did today we can win this."
The match starts at 2.45pm at the Gallagher Hockey Centre in Hamilton.