Jamie Jones-Buchanan marked his 300th Super League appearance by scoring a try in Leeds' Rhinos 30-18 win over St Helens on Friday and Warrington Wolves maintained their perfect start with a 56-12 hammering of Castleford Tigers.
The Rhinos have made a poor start to the defence of their title, but Brian McDermott's side ran in five tries at Headingley to seal only their second win of the season and end Saints' run of three consecutive victories.
Long-serving forward Jones-Buchanan got the champions off to a flying start when he took an offload from Keith Galloway and went over only three minutes in.
Saints were stunned when Adam Cuthbertson scored a second try a few minutes later and the Rhinos, still without captain Danny McGuire due to injury, were 16-0 up when Liam Sutcliffe raced 30 metres to touch down and convert his own try.
But Keiron Cunningham's men got going and turned the game on its head to lead 18-16 following tries from Kyle Amor, Luke Walsh and Louie McCarthy-Scarsbrook - with Walsh converting all three scores.
Leeds hit back with a Carl Ablett try to lead 22-18 at half-time and Ash Handley scored the only try of the second half, with Sutcliffe adding four points with the boot to consign Saints to a second defeat of the season.
Warrington make it six wins out of six to join leaders Widnes Vikings on 12 points with an 11-try demolition of Castleford Tigers.
The Tigers were totally outclassed at the Halliwell Jones Stadium, where Warrington ran in seven first-half tries to lead 38-0. Chris Sandow, Ben Currie and Tom Lineham scored their second tries of the game after the break on a miserable night for Castleford.
Former Hull Kingston Rovers coach Chris Chester's first game in charge of Wakefield Trinity Wildcats ended in a 22-4 defeat at Hull FC, so his new side remain second bottom.