Armstrong stars for Knights on debut to sink Dolphins

The Knights also lost forward Daniel Saifiti to a lower leg injury. 

Armstrong and Dolphins pocket dynamo Trai Fuller, in just his third NRL game, had a classic No.1 battle and were two of the best players on the field.

The 23-year-old Armstrong scored the opening try and made a try-saving tackle on Fuller in the second half. He was magnificent under the high ball and in general play with his elusive running.

Ponga is set to miss 12 weeks with a Lisfranc injury to his foot but Armstrong showed coach Adam O'Brien he was more than ready to play at the top level.

Fuller was electric and brave but his teammates struggled to get out of second gear until it was too late.

Knights props Leo Thompson and Jacob Saifiti, in his 150th NRL game for the club, ripped in early to set up a 10-0 lead as a sluggish Dolphins outfit bumbled their way through the opening quarter of the match.

The visitors were rewarded for their discipline and patience when half Jackson Hastings threw a sublime inside ball to Armstrong who sliced over untouched.

Five-eighth Tyson Gamble found veteran Dane Gagai with a slick pass and the centre showed his experience to hit a hole and score.

The Dolphins didn't get out of first gear until centre Jake Averillo blitzed opposite number Bradman Best and found second-rower Oryn Keeley, who scored his first NRL try against his former club. 

Dolphins forward Kenny Bromwich failed a category two HIA and Knights forward Jed Cartwright was ruled out with an ankle injury, both in the first half.

Gagai waltzed over after the break after pathetic defence by the Dolphins allowed bench hooker Phoenix Crossland to burst into the clear. 

The Dolphins bombed two tries, one when Averillo failed to collect a grubber kick through by Kodi Nikorima.

Nikorima set up Jamayne Isaako for a try and Averillo finished an electric movement, both in the last five minutes, but it was too little and too late.