(Reuters) - German fourth seed Alexander Zverev overcame tricky conditions to beat Hungary's Fabian Marozsan 6-3 7-5 on Thursday and reach the Miami Open semi-finals.

Zverev attacked Marozsan's serve and converted three of his seven break-point chances, swatted aside the two break points he faced and won 80% of his first serve points en route to the last four in Miami where he has yet to drop a set.