I think this means the manager retains the challenge if it is upheld. May be reading it wrong though. LFG
A manager may challenge as many reviewable calls within a single play as he desires using one challenge. The club retains its manager challenge if the replay official overturns any challenged call (even if he upholds other challenged calls), and loses its manager challenge if no calls are overturned. Once a club has exhausted its available manager challenge(s), it will no longer have the ability to challenge any additional play or call in the game.