Doctor Strange is one of the most powerful magic users in marvel universe, Stephen Strange has spent years achieving his magical capabilities, he may manipulate magic in any number of ways. He may travel in time, to other dimensions and places, Strange possess magical blasts and forcefields, basically Strange is capable of any magical feat.
Aquaman is the King of the Atlantains, because of his royal heritage he possess strength and abilities far above any member of his superhuman race, he also wields the Trident of Pisiden, this grants him the many godly capabilities, including weather and sea manipulation, godly blasts, and forcefields.
An excellent battle I'd say, I think it's more obvious that Strange will be victorious, his magical powers and versatility can't be matched.
Normally a human would lose against a member of a superhuman race, but Strange is at a level of magic, that can rival gods.