Vafaei defeated China's Zhang Anda 6-4 in quarterfinals.
The Iranian player will meet Ronnie O'Sullivan in the semifinals.
Vafaei, who has now racked up six centuries in the last two rounds, heads into their rematch as the form player after an unfocused O'Sullivan almost let a 4-1 lead slip against Chinese world No 26 Zhou Yuelong.
The pair have some history after Vafaei claimed he wanted to "shut" O'Sullivan up ahead of their World Championship match earlier this year, which the latter won 13-2.
"I'm going to try and keep up with him," the world No. 1 told Eurosport.
"He's playing really well, scored well last night. It was a different match against Anda he was playing a winner. Proper player.
"For him to win that is a proper win. I'm going to have to play well for 70-80% of the match to have a chance. If I go missing like I did I'll get beat, he's playing too well for that," O'Sullivan added.