Manly and Melbourne opened up a four-point gap at the top of the NRL table after the competition's two undefeated sides continued their flawless start to 2007 this weekend.

And to make matters worse, coaches Des Hasler and Craig Bellamy both warned there's still plenty of improvement left in their unbeaten sides.

The Sea Eagles kept up their incredible defensive record, conceding just one try to the Gold Coast Titans in Sunday's 20-8 victory at Brookvale Oval to continue to top the ladder with six wins.

Last year's minor premiers Melbourne trail Manly only on points difference after they held out fast-finishing Penrith on Saturday afternoon at Olympic Park to win 30-20.

Manly and Melbourne head the table with 12 points, North Queensland running third with eight points but a chance to move closer when they host South Sydney on Monday night.

However, after the top three there are seven sides locked on six points - New Zealand Warriors, South Sydney, Parramatta, Gold Coast, Newcastle, Cronulla and Bulldogs.

New Zealand Warriors will receive two for the bye to move into fourth at the completion of the round, while the Rabbitohs can also move up if they can claim an unlikely victory in Townsville.

Premier Brisbane recorded their second win of the season on Sunday, upsetting Newcastle's Andrew Johns farewell festivities with a 20-16 victory at EnergyAustralia Stadium.

Earlier Sunday Manly fullback Brett Stewart scored twice in the first five minutes to take his remarkable home ground tally to 33 tries from as many games.

The Eagles led 18-0 at half time and although they failed to kick on Hasler praised his side's committed defence which has now conceded just eight tries in six games.

"Our defence has been the cornerstone and it had to be today," Hasler said.

"But we certainly don't need to keep testing it and putting it under pressure like we did today.

"We got to Townsville next week (to play North Queensland) and we certainly need to step up."

Melbourne coach Craig Bellamy admitted his side had also failed to hit their straps so far this season, but is happy the Storm continue to grind out victories.

"We're not playing perhaps as well as we can skill-wise and technique-wise ... but I'd rather have a team play not as well as they could but show the intestinal fortitude these blokes do," he said.

The Bulldogs ended Parramatta's three-game winning streak today with a come-from-behind 21-18 win at Parramatta Stadium.

A Daniel Holdsworth field goal and late Hazem El Masri penalty booted the Dogs home after trailing 16-12 at half time.

"It wasn't pretty again, we certainly haven't hit our straps which is disappointing but I think on the positive we hung in there and defence got us home in the second half," said Dogs coach Steve Folkes.

Cronulla established themselves as the second best defensive side in the competition with a 26-0 win over Canberra on Saturday night at Toyota Park.

Centre Ben Pomeroy landed a hat trick, but more impressive for the Sharks it was the second time they kept a team scoreless at home following their 18-0 drubbing of Penrith in round one.

"We're really starting to set some standards with our defence and to keep them to nil, even though they didn't throw a great deal at us, you can only defend what they throw at you and we did that again," assistant Sharks coach Shane Flanagan said.

Brought to you by AAP © 2024 AAP