A disappointing three points in the third quarter could have proved disastrous, but the Coasters managed to contain their opponents and were clinging to a five-point buffer at threequarter-time.
The Phoenix got to within two points early in the final spell, but a gutsy 10 minutes from the Coasters kept their noses in front.
"The last game was always going to be a grind because it's physical and when fitness comes into play, sometimes your concentration goes a little bit," said Gwerder. "And the opposition was an incredibly physical team, which doesn't match us very well."
Her charges, however, held their own against the more experienced team.
"That's the mentality rather than physicality side of things — we've got skilled players but we really don't have too many bangers and that's what they had.
"We are still learning our rotation in regards to who plays well with who. But I felt all along that we'd get the job done.
"We are on a journey — we're building. It's only our second year in the programme, so we are learning along the way, but I'm excited about where we are at this stage," said Gwerder.
"If we look back at last year, we were competitive in limited games — this year we have been more competitive in two [against Te Tai Tokerau and Taranaki] and against the teams that are the powerhouses like the Junior Ferns and Waikato we actually held our own."
Gwerder said that while the Coasters' playing roster includes Charlotte Anderson, who is in her forties, there is plenty of young talent including 14-year-old Briarley Rogers, who is in the NZ under-16 lineup.
The WBC is the highest level of domestic competition for women. It is played over three events, with round two in Nelson next month and the final playoff series in Porirua in May.
"Obviously now we go back to training," said Gwerder. "There's a whole heap of things we have picked up from this tournament that we need to look at — mainly on the defensive side."