Serena Williams gets coaching violation from umpire Carlos Ramos

The 36-year-old, who was targeting a record-equalling 24th Grand Slam singles title at Flushing Meadows, angrily confronted umpire Carlos Ramos after being told off for what he deemed a coaching intervention.

Serena stormed up to his chair and informed him that she would never deliberately receive guidance from her coach, Patrick Mouratoglou, who was sat in the players' box.

She informed Ramos in strong terms:

Williams was clearly still fuming as she sat at the changeover at 2-1 up in the second set, before getting a point docked for hurling her racket to the ground, and then launching a series of tirades at the umpire, who sent her further into a rage when he handed her a game penalty for verbal abuse.

She followed that up by calling him a "thief" for taking a game away from her.

In a further exchange, Williams again informed umpire Ramos that she is not a cheat and did not receive coaching from Mouratoglou, even adding that she had a daughter so would not do that.

The confrontation came at a time when Williams perhaps needed a spark after she lost the opening set 6-2 to the dominant Japanese starlet.

The 20-year-old Osaka displayed an array of stunning groundstrokes in storming to a famous victory - Japan's first Grand Slam.