While the Giants completed an expected 32-14 win at Wakefield, Wigan were left regretting the decision to rest five regulars as they went down 37-36 at the basement club.
Huddersfield won a scrappy derby thanks to tries from Jermaine McGillvary (2), Joe Wardle (2), Larne Patrick and Kevin Brown to take over from Warrington at the summit.
Wakefield winger Ben Cockayne scored all three of his side's tries to lead a brief revival but Huddersfield started and finished strongly to deserve the points without playing anywhere near their best.
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Giants too strong for Hull, Dragons crush Vikings
16/03/2013 AT 20:48
Bottom club Widnes prevented Wigan going top thanks to a drop-goal from Lloyd White 10 minutes from time.
The Vikings looked down and out when they trailed 36-18 after 48 minutes, but hit back in style with tries from White, Shaun Briscoe and Frankie Winterstein - plus three kicks from Gareth O'Brien - bringing them level before White landed his dramatic one-pointer to seal a deserved victory.
Paddy Flynn and Stefan Marsh also crossed the whitewash for Widnes, while Briscoe also scored in the first half, while
Wigan's tries came courtesy of Matthew Russell (2), Gareth Hock, Harrison Hansen, Brett Finch and Joe Mellor.
Wigan had a late chance to win the match but Josh Charnley, who had booted six goals from six attempts, was off-target with a penalty.
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Youngquest stars for Tigers
07/05/2012 AT 20:32
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Kopczak injury blow for Bulls
05/03/2012 AT 22:38