The 21-year-old defeated world number five Karolina Pliskova to advance.
The Swiss broke a three-match losing streak against the Canadian
The Australian is one to watch in 2019
The Brit defeated Aliaksandra Sasnovich 6-2, 2-6, 7-6.
The 2009 Champion will look to win his second major title on Sunday against Novak Djokovic.
Williams defeated Sevastova in straight sets. Will face Osaka for title.
The two-time US Open champion will face Kei Nishikori next.
The twenty-three time major champion takes a step closer to another US Open title
In a battle of 20-year-olds, Osaka advanced 6-3, 2-6, 6-4.
The defending-champion advanced after a 6-3, 6-3 win.