Alexander Zverev suffers straight-sets defeat in first match as world No 1

Alexander Zverev suffered a straight-sets defeat in his first match as world No 1, losing to Italian player Lorenzo Musetti. The German's reign at the top of the rankings got off to a disappointing start in what was described as an upset result. Zverev had recently claimed the world No 1 ranking but was unable to mark the occasion with a victory.