Hawke's Bay opened up a five-point gap on their nearest rivals at the top of the second division NPC rugby competition with every indication they will continue to improve for the rest of the competition.

Their 40-14 win over the only other previously unbeaten team in the division, Nelson Bays, in Napier yesterday put them clear on top of the competition.

They lead with 23 points, followed by Nelson Bays (18), beaten five tries to one yesterday, and North Otago and Manawatu (15 each) after they scored solid wins yesterday.

While Manawatu travelled to Ruatoria and beat East Coast 17-8, North Otago made a hard job of their 36-29 home victory over Marlborough.

After a fine start by the home side during which they scored two tries, the Red Devils surpassed that lead and shot to a 29-12 advantage on the back of four consecutive tries -- three by New Zealand Colts winger Hayden Pedersen.

But North Otago, promoted to the division this year, kept Marlborough scoreless in the second half and came back to win handsomely after trailing by 17 points at one stage.

Defending champions Hawke's Bay remain the only unbeaten side in the entire NPC and showed enough strength and form at McLean Park yesterday to compete in the first division.

That could mean bad news for Northland, winless in the first division after five games, when the promotion-relegation game comes around.

Two of the Magpies' five tries came from New Zealand sevens star Tafai Ioasa.

Nelson Bays competed well in the first half which ended with the score 14-14, but they hardly fired a shot in the second as the home side's forwards continued the dominance they have had over all other opponents this season.

The Hawke's Bay backs produced their best effort of the season.

Though the lead changed five times during the closely fought first spell, the home side ran away with the game in the second half.

Manawatu earned four valuable points after taking advantage of the strong wind at Whakarau Park to lead 17-0 at halftime after right winger Taf Manyimo and No 8 Bryan Matenga scored.

They held on in the second half even though Kahu Tamatea kicked a penalty goal and scored a try for the home side.

"We used the conditions to our advantage in the first half," Manawatu coach Ken Maharey said.

North Otago came from 12-29 down to beat Marlborough 36-29.

The Red Devils did everything to win the game but couldn't hold on to their 17-point advantage which they had just before halftime.

Pedersen sparked Marlborough's superb effort to blot out North Otago's early lead. He scored three tries with his blistering pace and an impressive show of strength.

Hooker Mark Stewart also dotted down and Marlborough looked in full control when leading 29-12.

However, North Otago signalled their intention when centre Mike Mavor scored just before halftime.

Then winger Watisoni Lotawa broke the line and popped up an over-head pass metres from the line and second five-eighth Steve Kotua gratefully took the ball and scored.

North Otago grew in confidence and added another two tries through the barnstorming prop Atalea Katoa and Mavor.

Counties Manukau's 57-23 win over Thames Valley gave them maximum points and despite their eight tries, coach Bruce Robertson wasn't happy with the 17-7 penalty count against them.

Fijians Sitiveni Sivivatu (wing) and Sailosi Tagicakibau (fullback) scored two tries each for Counties.