Serena Williams dispatched sister Venus Williams with a 6-2, 1-6, 6-3 victory on Tuesday night, advancing to the semifinal round of the 2015 US Open and moving to within two wins of the first grand slam in a calendar year in 27 years.

No. 1 seed Serena had 12 aces in her victory over No. 23 Venus, her second win against her older sister in two meetings this season, having also beaten Venus 6-4, 6-3 in the Wimbledon quarterfinals.

The two sisters have now met 27 times in their career, with Serena prevailing 11 times. Serena improved to 3-2 all-time against her sister at the US Open, having also won the 2002 final and 2008 quarterfinal.

Serena has dropped just two sets so far in the tournament, and will face unseeded Roberta Vinci in the semifinal round. This is the fifth straight year and seventh time in the last eight years that Serena has reached at least the semifinal round at the US Open. She has won the tournament the last three years, and six times overall.

A tournament win for Williams at Flushing Meadows would not only give her five straight grand slam tournament wins and the first calendar-year grand slam since Steffi Graf in 1988, but it would also tie Graf with 22 grand slam singles title, second all-time to Margaret Court.