Wigan coach Shaun Wane says his side played dumb in their last-gasp defeat at Castleford - who he admitted deserved their victory.
Warrington coach Tony Smith admitted his side had to work hard to see off a battling London side 44-16 in the capital.
Wakefield head coach Richard Agar refused to get carried away despite watching his side inflict a crushing 56-14 defeat on Catalan Dragons.
Castleford maintained their early-season Super League form with a 36-31 victory over Wigan, while Warrington and Wakefield also grabbed wins.
Castleford maintained their early-season sparkle with a first home win over Wigan for eight years after edging a thriller 36-31 at the Jungle.
Taulima Tautai was in destructive form as Wakefield routed Catalan 56-14 to record their first victory of the Super League season.
Rhys Evans ran in four tries as Warrington subdued a feisty London 44-16 in the capital on Sunday.
Hull KR have moved to ease their injury crisis by signing St Helens winger Ade Gardner on loan.
England stars Sam Tomkins and Gareth Widdop enjoyed contrasting fortunes on debut for their new clubs in the first round of the NRL on Sunday.
Unbeaten Castleford face the acid test of their improvement with the visit of Super League champions Wigan, according to coach Daryl Powell.
Something will have to give at the Rapid Solicitors Stadium where Wakefield and Catalan Dragons will seek their first points of the season.
Warrington half-back Gareth O'Brien is confident his side will make it back-to-back wins when they take on London Broncos at The Hive.