The New Zealand under-20 representative showed perfect timing to dive over in the corner, touching down a split second before Bay winger Sinoti Sinoti slammed him into touch.
Goodman couldn't make the wide conversion and Hawke's Bay led 6-5 after 20 minutes, extending the margin three minutes later with a third Buckman penalty.
Tasman reclaimed the lead with two Goodman penalties, and the first half looked set to wind down with the visitors leading 11-9.
A man down after tighthead prop Anthony Perenise was yellow-carded for a deliberate knock on as Tasman attacked their line, Hawke's Bay snared the halftime lead barely a minute from the break.
Hurricanes flanker Karl Lowe powered over as Hawke's Bay's maul, backed up by a snappy pick and go, forced a path through the Tasman defence.
Buckman couldn't make the conversion, and the Bay went into the break 14-11 up.
Tasman levelled five minutes into the second half with another Goodman penalty, and the scores remained tied until replacement flanker Adam Bradey peeled off an attacking Hawke's Bay scrum to bulldoze over for the try.
Buckman couldn't add the extras, and Tasman regained the lead five minutes later. No 8 Mark Bright -- rested for the first half after playing all four previous games -- showed excellent strength to smash through the Hawke's Bay line defence to touch down.
Goodman's conversion made it 21-19, and Tasman defended well to hold off the Hawke's Bay onslaught, then showed good control to keep the ball in tight and shut out the win.
- NZPA