Ons Jabeur of Tunisia celebrates after defeating Ajla Tomlijanovic of Australia during their Women s Singles Quarterfinal match on Day Nine of the 2022 US Open at USTA Billie Jean King National Tennis Center on September 06, 2022 in the Flushing neighborhood of the Queens borough of New York City. AFP
Jabeur, who was also the first woman from Africa to win a place in the Wimbledon final in July, moved into the last four with a 6-4, 7-6 (7/4) win on the Arthur Ashe Stadium Court.
The 28-year-old will face either 12th seed Coco Gauff or in-form French 17th seed Caroline Garcia in Thursday's semi-finals.
Tomljanovic's run to the quarter-finals had included a superb display to eliminate Serena Williams in the third round, in what was most likely the 23-time Grand Slam champion's final singles match before retirement.
But Tomljanovic found the going harder against the dynamic Jabeur on Tuesday, the Tunisian varying her play cleverly and attacking her Australian opponent from the outset.
Jabeur said she drew confidence from reaching the Wimbledon final, and hoped her success would inspire future generations of female African tennis players.
"It really means a lot to me," Jabeur said.
"I believe more in myself. After Wimbledon it was very positive. Even though I lost the final, I knew I had it in me to win a Grand Slam. And here I am in the semi-finals of the US Open."
Jabeur is known affectionately as the "Minister of Happiness" by fans in Tunisia for the joy that her progress on court has brought to her homeland.
However Jabeur admitted she had let her frustration get the better of her at times on Tuesday, when she banged her racquet in frustration several times.
"I think I'm gonna be fired from my job as Minister of Happiness," she joked.
"It is tough to manage my frustration. I apologise for my behavior. I really wanted to keep calm but the racquet kept slipping away from my hand."
Jabeur broke early on to set up a 3-1 lead in the first set and although Tomljanovic broke back to level at 3-3, Jabeur regained the advantage in the next game, sealing a break with a pinpoint backhand winner into the corner before holding for 5-3.
Tomljanovic staved off a set point to cut Jabeur's lead to 5-4, but Jabeur held serve easily, bringing up two set points with an ace before clinching the opening set when a Tomljanovic return sailed long.
Jabeur looked poised to wrap up victory briskly after grabbing an early break and a hold to go 2-0 early in the second set.
But the Tunisian was then broken three times in a row to leave Tomljanovic serving for the set at 5-3 up.
Tomljanovic's nerve failed her however and she double-faulted at 0-40 down to throw Jabeur a lifeline. Jabeur took full advantage to force the tie-break and clinched victory when a Tomljanovic return plopped into the net.
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