Hull FC held off an incredible comeback from Wakefield Trinity, but Marc Sneyd only secured the win in golden-point extra time.
Warrington Wolves were shut out at Headingley as Leeds Rhinos scored six tries without reply to make a statement.
Castleford Tigers beat Wakefield Trinity for a 14th straight time, as Huddersfield Giants and Warrington Wolves also claimed wins.
St Helens are top of the Super League table with three games played after they beat Hull FC 32-18, while Wakefield Trinity beat Warrington.
Warrington Wolves have stood down Anthony Gelling as they probe his "conduct away from the club".
St Helens failed to score as Warrington claimed a big Super League scalp, thanks to tries from Daryl Clark, Tom Lineham and Josh Charnley.
Warrington Wolves were reduced to 12 men early on against Wigan Warriors, who ultimately saw out a cagey win to start their season in style.
Leilani Latu will get his first taste of Super League with Challenge Cup holders Warrington Wolves.
Gareth Widdop will miss the start of the Super League season after suffering an injury which could keep him out until after round four.
Catalans Dragons and Warrington Wolves have been hit in the pocket due to ugly scenes in the south of France.