Wellington put on perfect weather conditions this year for a fast and tactical race, which Robinson revelled in.
The Gisborne athlete sat comfortably in the pack behind Gualter for the first 15km.
With 6km to go, Robinson decided to make a move and Speakman went with him.
The two runners surged clear of the pack and stayed together until Speakman pulled clear 300 metres from the finish line.
Robinson, coached by former Gisborne international triathlete Josiah Ney, had been running up to 120km a week leading into the event.
“It was a very enjoyable race,” said Robinson. “I thought I could nudge out Speakman for second. It is the first time I have been in a position to do that and be confident enough to stick it out.”
Gisborne-based Joshua Stewart, representing Hawke’s Bay, also ran a PB of 1h 11m 42s to place 15th.
Wellington’s Sarah Drought, the defending women’s champion, won by more than two minutes and broke her own race record with a time of 1h 15m 44s.