Freddy Guilber gave the lead to Aston Villa from the first goal for the away team in the 28th minute, but Lester, second in the Premier League who hopes to reach the first cup final since 2000, shook the net through Clichy Ihenacho to equalize in the 74th minute.
The return match will be played on January 28th, with the winner in the final playing against Manchester City or Manchester United.
Leicester striker Jimmy Vardy returned to his team after being missing from the last three games due to a minor calf injury, while Jonathan Kodjia Aston Villa, who is 17th in the league, was left without a striker.
Aston Villa coach Dean Smith said, "We had no choice. This is our situation."
A pass made by Ayuzi Perez, who changed her direction outside the field, and Aston Villa goalkeeper Urien Niland deflected an attempt by Vardy with his knee as the initiative was from Leicester, but the away team was the one who grabbed the progress.
Jack Greelish began an attack that reached Anwar al-Ghazi, who sent a cross pass around Goylber with a direct shot.
Aston Villa almost strengthened their lead ahead of the break, but Izro Konza's header hit the bar.
Lester pressed in the second half and it seemed that Aston Villa would stand up to the fact that Hamzah Chaudhry snatched the ball from Douglas Louise and started a counterattack that Fardi prepared for Ihenacho who put it in the net.
