Hawke's Bay raised their bonus point before halftime tonight against a bumbling Counties-Manukau to skip to the top of the Air NZ Cup rugby competition alongside Auckland.

Both teams are on 20 points, with Auckland still holding an edge on the points differential, with their fifth-round match against Taranaki to be played tomorrow.

Whatever the rest of the results in the round, however, Hawke's Bay will remain in the top four.

Hawke's Bay will host Auckland in Napier in the next round next Thursday and will face a sterner test than they had over the last few rounds.

Centre Jason Shoemark, halfback Danny Lee, hooker Hika Elliot and lock Matt Egan scored a try each before halftime to earn their team a bonus point at Mt Smart Stadium in Auckland.

First five-eighth Matt Berquist kicked three penalties and three conversions in the 35-0 halftime lead. He added another penalty in the second half for an 18-point haul.

Penalty points aside, all four first-half Hawke's Bay tries were results of Counties errors, mostly carelessness.

Berquist kicked a penalty in the third minute and only seconds later Shoemark charged down a kicked from first five-eighth Tanner Vili to score.

Berquist converted and added two penalties before Counties turned over the ball again and prop Fafa'anaua Taumalolo started the counter-attack which Lee finished. However, the try should not have been awarded as Shoemark was well in touch in a tackle during the attack and passed back in.

Elliot scored as a result of a counter-attack that was started after Vili chucked the ball blindly back while Counties were hot on attack.

Taumalolo featured again in a powerful run which opened the way for Hawke's Bay's bonus-point earning try which could have been scored by any four players in support of Lee, who sent a long pass to Egan to finish it off.

Counties lifted their game, stopped throwing risky passes and Vili and replacement Chad Tuoro scored two quick tries after halftime to close the gap to 35-14.

Counties winger Lelia Masaga showed his class yet again, featuring in some penetrating runs and proving hard to stop.

But Counties were their own worst enemies, with careless passing and recklessness costing them points both ways -- denying them tries and enabling Hawke's Bay to score off them.

"It's pretty exciting for the boys but in the next few weeks we've got a pretty hard road," Lee said of their matches against Auckland, Canterbury, Northland and Waikato.

"Tactically we're doing things really, really well. We've got a good team unity this year and that really helps."

Counties captain Kristian Ormbsy said his team let themselves down with too many turnovers and knock-ons.

"When they hit back they had support all round."

Hawke's Bay beat Counties-Manukau 38-14 in their Air NZ Cup rugby match at Mt Smart Stadium, Auckland tonight.

Hawke's Bay 38 (Jason Shoemark, Danny Lee, Hika Elliot, Matt Egan tries; Matt Berquist 4 pen, 3 con), Counties-Manukau 14 (Tanner Vili, Chad Tuoro tries; Vili 2 con). Halftime: 35-0.