"Let everyone keep kicking," the fourth-year coach said. "The boys have worked very hard over the last 16 weeks and a lot of blokes have been kicked during that period.

"It's good to see them pull together and play like they train. They got off their line hard, backed their fitness and came up well."

The Dragons' 32-point demolition of Penrith made a mockery of the pre-season prediction that heralded this young Panthers outfit as one of the dominant forces this season.

Those same crystal-ballers were also writing off the Dragons, deriding the lack of attacking flair that plagued them last season. The 42 points St George Illawarra put past Penrith on Saturday in front of 7283 fans at UOW Jubilee Oval was more than the club amassed in the first six rounds last year.

"I don't really want to talk about last year to be honest, it's gone," McGregor said.

"The boys listened well, they trained hard and they've got the rewards. And we're playing a style the boys are liking because they can play whatever's in front of them.

"You shape your season through pre-season. We've got new staff to be honest, and with new staff brings change.

"Nathan Pickworth, our performance manager's got some guys from AFL so we've done a lot of running. I'm staying right out of that department, it's something I crossed over [into] too much last year in different roles."

McGregor has said he wants the fittest side in the NRL competition this season, and that's exactly what he appears to have at his disposal.

They were led by a monstrous forward pack boasting irrepressible recruit Paul Vaughan, three-try hero Joel Thompson and the barnstorming Jack de Belin, who is on the verge of a contract extension with the Red V.

St George Illawarra's big men were well supported by new hooker Cameron McInnes, who was assured out of dummy half, Josh McCrone, who steered the ship nicely wearing the No.7 jersey that Ben Hunt has been expensively recruited to fill next season, and captain Gareth Widdop, who produced a performance typical of his vintage that included two tries.

"Our strength is in our forward pack, we've got two experienced front-rowers coming on for two experienced [ones] that come off - not many clubs do have that and it works really well," McGregor said.

"I'm carrying that fourth person on the bench as more of a utility this year where I shared the minutes last year, but the guys are a lot fitter so I expect them to play more minutes."

That utility was young half Jai Field, who took the field with 10 minutes to go when the result was firmly in the bag, McCrone and Widdop having steered the ship perfectly to that point.

They completely outplayed their opposite numbers. Nathan Cleary was invisible for most of the game while Te Maire Martin, back from a shoulder injury that curtailed the back end of his 2016, was unable to influence the result.

Powerful recruit James Tamou was well below his best while Trent Merrin was quiet by his high standards.

"Defensively we weren't at the same intensity as they were," Panthers coach Anthony Griffin said.

"That's a credit to them, they came at us really hard, both with the ball and without the ball. In the end, it led to us making a lot of errors. They were just far too good.

"You could feel it watching it, once they got a run of possession early. It's a tough competition and they've got a big forward pack with a lot of ball and they were just too good for us today."

Griffin said his team hadn't been affected by the pre-season hype surrounding his club. "That's not anything we speak about," Griffin said.

"We come here today and obviously we were looking forward to round one. Just got really jumped early with that run of possession and never recovered.

"It's just disappointing from a team point of view, but it's round one."