Raiders center Nick Cotric has been felt in his team's Sunday night clash against the Dragons in Wollongong.
With his team up 26-10 with just over 20 minutes to go, upside down center
Referee Ashley Klein banished the NSW State of Origin representative to the sheds. Lafai was treated by Dragons medicos but remained on the field.
It was the first send-off since Storm center Curtis Scott was marched for punching Manly's Dylan Walker last year.
"I didn't quite see it but I remember my head just spinning," Lafai told Fox Sports in an interview straight after full-time. "It is what it is. It happens in the footy, it's all part of the game I guess."
The send-off took the gloss off to record-breaking night for captain Jarrod Croker as the Raiders shored up to top-four spot and all but end St George Illawarra's finals hopes with a convincing 36-14 win in Wollongong on Sunday night.
Croker went past namesake Jason Croker into outright first place on Canberra's try-scoring list with his 121st career
Bailey Simonsson early in the second half following short-range tries in the opening 40 from Cotric in his injury return and Joe Tapine.
Charnze Nicoll-Klokstad also crossed by short range after Simonsson to make it 26-0, with the Dragons defense found
Korbin Sims crashed over to get the Red V on the board in the 49th, which was quickly followed by Luciano Leilua four-pointer.
Despite being at the bottom of the Raiders were still able to have their own mini-slump but pushed ahead by trying to Siliva Havili and Nicoll-Klokstad's second part of the Dragons notched a consolation try in the closing stages against the 12-man line-up via Matt Dufty.