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Andy Murray took the row about equal pay in tennis onto Twitter as he traded blows with Ukrainian rival Sergiy Stakhovsky.
Stakhovsky is a long-standing and vocal critic of equal prize money for women. The topic has dominated headlines over the past few days following comments from former Indian Wells tournament director Raymond Moore.
Moore resigned on Tuesday after saying the women's game "rides on the coattails of the men" and that female players should "go down every night on (their) knees and thank God that Roger Federer and Rafa Nadal were born''.
Moore apologised but the damage was done, and equal prize money dominated the conversation at Tuesday's media day at the Miami Open.
Murray is the leading advocate among male players for equality in all its forms and he was predictably forthright on the subject.
The world number two said Moore's comments "made no sense at all" and also took on Novak Djokovic, who fanned the flames in Indian Wells by saying the ATP should push for more money because men's matches are more popular.
Murray responded with a pointed dig at Stakhovsky, the player he beat in the US Open junior final in 2004, saying a lot more people would watch a match at Wimbledon involving Laura Robson than the Ukrainian.
In a lengthy exchange on Twitter, Stakhovsky said to Murray: "Thanks for mentioning me today. Need some attention. Although your argument fails the moment we leave UK territory."
Murray hit back: "As soon as we leave UK territory more people are watching you than Laura? Really?"
Stakhovsky, ranked 115, replied: "The venue in Kiev is ready. All you need to do is convince Laura to come."
Murray then brought up a match between the two in Davis Cup in 2006, which he won 6-3 6-2 7-5 to clinch the tie for Britain.
"I played you in a Davis Cup match in Ukraine and there must have been a thousand people there max!" said Murray.
Stakhovsky responded by questioning how many empty seats there were, to which Murray said: " How many empty seats were there Serge? I wasn't counting was focused on the getting the W (win)."
Serena Williams was also critical of her fellow world number one Djokovic, saying: "Novak is entitled to his opinion but if he has a daughter - I think he has a son right now - he should talk to her and tell her how his son deserves more money because he is a boy."
Djokovic sought to repair the damage with a post on Facebook on Tuesday evening, insisting he had been misunderstood.
He wrote: "Tennis helped me so much in my life and being where I am today, I felt the need to speak about the fairer and better distribution of funds across the board - this was meant for both men and women. We all have to fight for what we deserve.
"This was never meant to be made into a fight between genders and differences in pay, but in the way all players are rewarded for their play and effort.
"Tennis is a sport that I love and that gave me the opportunity to help others who still have a long way to go to achieve their dreams. This was my view all along and I want to apologise to anyone who has taken this the wrong way."
Murray will begin his campaign in Miami on Saturday against either Borna Coric or Denis Istomin.