George Bridge scored his second successive hat-trick as Crusaders maintained their perfect record in Super Rugby, but Kieran Read's broken thumb will be a worry for New Zealand ahead of the British and Irish Lions' tour.

All Blacks captain Read requires surgery on the injury sustained in Sunday's (AEST) 48-21 defeat of Cheetahs and could be a doubt for the first Test against Warren Gatland's side, which takes place on 24 June.

The setback tarnished an otherwise excellent day for Crusaders and Bridge in particular.

The wing crossed the whitewash three times in a 57-24 rout of Stormers last time out, and he repeated the feat as Crusaders made it nine wins from nine.

Last crowned champions in 2008, Crusaders look well set to feature heavily in the end-of-season shake-up as they delivered another strong performance at Free State Stadium.

David Havili was first to go over, Bridge touching down for his first before Cheetahs had a Sergeal Petersen try controversially ruled out for a forward pass which television replays suggested was not the case.

Bridge rubbed further salt into the wounds with his second to give the visitors a 22-7 half-time lead. That was extended as Richie Mo'unga went over soon after the restart, Havili adding his second before Mitchell Drummond got in on the act.

Bridge's third rounded off the scoring for Crusaders, who lost Sam Whitelock and Mitch Hunt to yellows in the final 10 minutes, Petersen adding a meaningless score for Cheetahs at the end.

Meanwhile, Sharks overcame Jaguares 33-25 and, in a one-sided affair, Southern Kings routed Rebels 44-3, the home side running in half a dozen tries, including 33 unanswered second-half points.