Elina Svitolina will have to focus on countering Serena Williams' most powerful weapon – her serve – to have a chance to advance to the US Open final.
Analysis: Serena Williams' service game will be deciding factor in US Open semifinal
Elina Svitolina will have to focus on countering Serena Williams' most powerful weapon – her serve – to have a chance to advance to the US Open final.
