Warrington Wolves ran out 28-16 winners in their top-of-the-table Super League clash with Wigan Warriors at the DW Stadium, but the victory came at a potentially heavy cost as Chris Sandow and Rhys Evans picked up injuries.
Scrum-half Sandow was hugely influential in the opening quarter on Friday, laying on three tries as the Wolves - beaten for the first time this season at Hull FC on Monday - seized command of proceedings.
However, the Australian was then withdrawn with a hamstring problem, after Warrington's options had already been limited by a potentially serious shoulder injury sustained by centre Evans.
Tony Smith's men were nevertheless able to cash in on their early breakthroughs and move two points clear of Wigan, who saw their own significant injury woes added to by skipper Sean O'Loughlin's enforced withdrawal at half-time.
Winger Dom Manfredi claimed a hat-trick of tries for the Warriors, but it was not enough as Warrington deservedly got back to winning ways.
Last season's treble winners, Leeds Rhinos, suffered yet another hugely disappointing setback, going down 30-10 at home to fellow strugglers Hull KR.
The Rhinos have now lost seven of their nine league matches this season, having also been thumped by North Queensland Cowboys in the World Club Challenge.
The latest loss for Brian McDermott's champions, which saw them slip to 11th behind Rovers, featured two tries for Shaun Lunt.
In Friday's other match, Hull FC followed up their win over Warrington with a fourth successive victory, Marc Sneyd's late drop goal enough to seal a dramatic 17-16 triumph over St Helens.