The news of coaching switches over the past week threw up a win for the Cowboys but the other teams concerned all slumped to losses.
Johnathan Thurston's return to form resulted in the North Queenslanders rolling fancied Parramatta 38-14 in front of 19,231 for their first win ofthe season.
Prop Carl Webb scored after three minutes and again mid-half to spark a seven-tries-to-two victory, 38-14, the team's points beating the total from the first three rounds.
The judiciary will look at a lifting tackle on Cowboys lock Luke O'Donnell, with Joel Reddy, Brett Finch and Daniel Wagon in the frame.
The Cowboys are away to the Dragons next week.
News that Wayne Bennett will take over from Nathan Brown midweek was not enough to drive St George to a win over the Sharks on Saturday.
The Dragons led all the way, bar the last minutes when wing Bryson Goodwin dotted down a Greg Bird grubber to level scores at 16-all.
Two minutes into extra time, prop Jason Ryles was penalised for a hold-down in the tackle and Kiwis wing Luke Covell kicked the goal from 41m for an 18-16 win.
Canberra's Neil Henry, who transfers to Townsville next season, is likely to have to rejuggle his forward pack for the next round at home to the Tigers as Michael Weyman faces a long stint suspended for a king hit on the Gold Coast's Daniel Conn.
Weyman was sent off and Conn had to leave with facial injuries. The Gold Coast then added two tries while Canberra were down to 12 men to skate away to a 32-12 win.
As they head for their clash with Parramatta next weekend, co-captain and prop Luke Bailey is suffering a hand injury and wing Jordan Atkins a knee tear.
The judiciary will study a tackle by the Storm's Kiwis prop Adam Blair on Brisbane's Michael Ennis as the title holders won 28-8 in Melbourne.
The Broncos claimed Melbourne had developed a "chicken wing" tackle where the non-ball carrying arm of an attacker is held and twisted and that Blair put one on Ennis.
The Roosters were comprehensive 32-12 winners over the Bulldogs in Friday's grudge match. The Roosters travel to Penrith next weekend while the Bulldogs come to Mt Smart to play the Warriors on Sunday.
