As injuries and State of Origin absences depleted both sides, Lucas showed his potential as a future NSW player, helping the struggling Knights ease pressure on coach Adam O'Brien with an improved attacking performance.
Fletcher Sharpe excelled replacing Queensland's Kalyn Ponga at fullback, scoring the Knights' first try at close range to trigger a game-defining 24-0 first-half skirmish.
"I'm so happy for them, one by one as they came into the sheds you can just see everything: Relief, certainly happiness," O'Brien said on Saturday night.
"I know a lot will be written that it was understrength Penrith but seven of our best players are out. So I don't want to hear that story.
"We're not out of it (our slump) yet, there'll be more written about us at some point, we've just got to focus on putting in performances like that more often."
Penrith's five Origin absences notwithstanding, O'Brien may have found the solution to his long-running halves problem as five-eighth Tyson Gamble laid on all three of Lucas' tries.
Two came from beautiful flat balls in back-to-back sets before Gamble put boot to ball and helped the second-rower make it a four-score game after 25 minutes.
Lucas could've had a fourth try in the shadows of halftime had he not spilt the ball over the tryline.
Sharpe, meanwhile, finished with a staggering 16 tackle busts and four line breaks to go with a game-high 284 metres and was the Knights' best in a more even second half.
Adam Elliott tore a bicep in the first half as the only sour note for Newcastle.
The loss laid bare the mighty task ahead of the Panthers to salvage an already dire campaign in the always-testing Origin period.
The Panthers mercifully have byes before the final two Origin games but may need to rest players after game two given a trip to Auckland three days later.
Goal-line defence was again a major issue for Penrith in the first half, with back-up halfback Brad Schneider targeted by Lucas ahead of his first two tries.
"I'm just super disappointed with the start," said Panthers coach Ivan Cleary.
"A game like this when you're obviously down on troops, it's the worst start we could find. Confidence was down early and it became a pretty tough night.
"I was obviously much happier with the second half but it would've been nice to have seen that in the first half."
Penrith are now one point adrift at the bottom of the ladder.
"It's not where you want to be," Cleary said.
"We've already shown this year that we have the potential to be doing much better. But you can only rely on potential for so long."
Penrith could lose prop Liam Henry to suspension for a crusher tackle on Sharpe that landed him in the sin bin and put the Knights in position for their fourth try.
Highly-touted forward Harrison Hassett cut through for a try on debut in the second half.
But that was good as things got for Penrith as former Panther Jack Cogger put the cherry on top with a field goal as the last five minutes approached.
Newcastle debutant Paul Bryan dislocated his shoulder in his first minute but played on after it popped back in twice.
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