An Anthony Milford-inspired Canberra left it late to put away Newcastle on Sunday night but their 26-20 NRL win was soured by an ankle injury to backrower Josh Papalii.
The hard-running Queensland and Kangaroos forward was assisted from the field early in the second half after falling awkwardly in a tackle and played no further part in the Hunter Stadium clash.
Papalii is likely to have scans on Monday to assess the severity of the injury and the Raiders can ill-afford to have their most damaging ball-runner unavailable so early in the season.
The injury somewhat overshadowed the freakish performance of one of their other talented game-breakers.
Exciting fullback Anthony Milford had a hand in three of his side's five tries to give Canberra their first victory of the season in front of a crowd of 14,674.
"They turn games, class players," Raiders coach Ricky Stuart said of Milford.
"On the back of all the grunt and the grind, and the effort from a number of individuals in the team, his bit of class was a big part in the (win)."
With 12 minutes remaining and the Knights leading 20-16, Milford provided the spark with a 40m burst that led to Paul Vaughan diving over.
Edrick Lee's last-minute four-pointer sealed the triumph to leave the Knights winless after two rounds.
Newcastle coach Wayne Bennett was far from impressed that the pass from Raiders centre Jarrod Croker to Vaughan for the crucial try that levelled the scores wasn't pulled up.
Referee Adam Devcich looked set to call it forward, putting his whistle to his mouth but allowing play to continue as Vaughan set sail for the tryline.
"I think it was pretty obvious to everybody at the ground (it was forward). There is not a lot of luck going our way (with calls)," Bennett said.
"Three or four things tonight was line ball stuff and didn't go our way. In a tight game like that, that's the difference.
"It was a much improved effort on last week. We were a bit stiff to lose there tonight. We didn't play badly. We played a quality game of football."
Croker scored two tries for the Raiders and Josh McCrone got the other four-pointer for the visitors with a slick dart from dummy half.
Knights debutant Matt Minto was involved in Newcastle's first try when he delivered a cut-out pass to send winger Akuila Uate on a 30m run to the tryline while second-rower Beau Scott's powerful try was the highlight of the first half for the home side.
An in-goal collision between Reece Robinson and Milford led to Knights winger James McManus planting the ball down in the 59th minute to leave Newcastle behind 16-14.
Then halfback Tyrone Roberts stepped past prop Brett White to score a 30m try to give the Knights a four-point lead after 65 minutes before Milford's match-turning run.
Canberra second-rower Joel Edwards was placed on report for a lifting tackle on forward Chris Houston shortly before halftime.
- AAP