Waikato's attack-minded approach was rewarded with five points and a big move up the standings following a 45-33 win over Northland in an entertaining national provincial championship rugby match in Whangarei today.

Both teams made good use of perfect conditions for running rugby by scoring five tries each in a match that appeared destined to go to wire until Waikato wrestled free midway through the second half, with successive tries to impressive wing Henry Speight and first five-eighth Stephen Donald, who tallied 25 points.

Speight was a constant threat for the visitors, providing the final pass for two tries and setting up a third before finally scoring one himself.

Waikato moved from seventh to a tie for second with Canterbury following the bonus-point win.

They now have 31 points, three less than leaders Southland, though both Southland and Canterbury are yet to play this weekend.

Northland's top seven hopes were dealt a blow. They are ninth, but six points adrift of seventh-placed Wellington.

It wasn't all good news for Waikato, however, with halfback Brendon Leonard, who had scored two tries, stretchered from the field and taken to hospital in a neck brace following a head clash with Northland fullback Lachie Munro.

Tensions boiled over late in the match with an all-in scuffle after a late hit by Waikato's Vern Kamo, who spent the final eight minutes in the sinbin, but Waikato had built a 14-point lead by that stage.

A frenetic first half saw six tries scored, including four inside the opening 15 minutes as both teams took the opportunity to attack in ideal conditions.

Both teams were impressive with ball in hand, mixing forward grunt with some lovely touches out wide.

Leonard (twice) and centre Save Tokula crossed for Waikato while Mateo Malupo, Munro, and Cameron Eyre scored tries for the home team, who trailed 20-22 at halftime.

Midway through the second half Speight scooted away for a try and Donald dotted down 5min later - after prop Nathan White grasped an intercept and offloaded to him - to put Waikato 16 points clear.

Substitute Mikaele Tuu'u and flanker Dean Budd scored a late tries for Northland but Waikato had created enough breathing space, with Donald's kicking radar on song and Munro missing with four of five conversions.