Penrith has shot to its best start to an NRL season in 19 years – but with an injury crisis brewing, it is going to need it.

Panthers coach Anthony Griffin is running worryingly low on outside backs after winger Josh Mansour suffered a suspected fractured jaw in Sunday’s 35-12 demolition of the Gold Coast at Panthers Stadium.

Mansour went down after being hit with an accidental flying knee by Anthony Don as the Titans winger leapt to contest a Kane Elgey bomb.

Mansour was taken to hospital and early indications are that he will miss around six weeks.

After 119kg back-rower Viliame Kikau was at times forced to fill in on the flank in the second half, it leaves the Panthers short a specialist winger for next week’s clash against Cronulla.

Dallin Watene-Zelezniak (jaw) must receive doctor’s clearance but had been pencilled in to return the following round.

Waqa Blake (ankle) and Tyrone Philips (pec) are also still several weeks away.

Another option would be to move Tyrone Peachey from five-eighth back into the centres but with Tyrone May (knee) and Nathan Cleary (knee) in the recovery group, they are also short on back-up halves.

Panthers players celebrate after Corey Harawira-Naera scored a try against the Titans. Photo: AAP

After jumping to 5-1, it’s Penrith’s best start since 1999, although Griffin will be reminding his troops that the Panthers that year lost 10 of their last 15 to miss the finals.

“It’s good reward for all the work they’ve put in but we’re only a quarter of the way through the season,” Griffin said.

“It’s nice to be in that position, we don’t want to look too far ahead, we’ve just got to move onto Cronulla next Sunday.

“The players have worked extremely hard and we’ve overcome a few obstacles early in the year with injuries and a few things like that.”

Penrith’s win, combined with the Wests Tigers’ 38-12 flogging of Manly on Sunday, has opened a four-point gap between the top four and the chasing pack after just six rounds.

Melbourne has gone fifth following its defeat of Newcastle on Friday, while the Sydney Roosters are back in sixth after their loss to seventh-placed South Sydney.

Jaydn S`ua may have lost this battle to Peta Hiku but the Broncos won the war against the Warriors. Photo: AAP

Brisbane is also back in the eight courtesy of its effort to knock off the previously undefeated Warriors on Saturday.

The plight of early-season favourites North Queensland, Parramatta and Cronulla continued to suffer.

The Cowboys have now lost five straight for the first time since 2013 after their loss to Canterbury, while Parramatta must now become the first team ever to come from 0-6 to make the finals.

The Sharks also lost their four biggest-name forwards – Andrew Fifita, Paul Gallen, Luke Lewis and Wade Graham – to injury in their 20-point loss to the undefeated top-of-the-table St George-Illawarra.

-AAP