Complex sentence: During the match, Hingis had infuriated an already partisan crowd by arguing with the umpire over several line calls (crossing the net in one instance), taking a bathroom break early in the final set, and twice delivering underhand serves.
Split into simpler sentences: During the match, Hingis had infuriated an already partisan crowd by arguing with the umpire over several line calls. She was also booed for taking a bathroom break early in the final set, and twice delivering underhand serves.