Sofia Kenin kept her game neat and tidy to see off big-hitting Tunisian Ons Jabeur 6-4 6-4 at the Australian Open on Tuesday and reach her first Grand Slam semi-final.
The 21-year-old American arrived in Melbourne after a breakthrough 2019 season when she won all three of her WTA singles titles and came in to Tuesday's clash at Rod Laver Arena with a 3-1 record against Jabeur.
Perhaps aware she did not have the power to match her opponent, Kenin instead focused on keeping her error count to a minimum.
Jabeur, the first Arab woman to reach a Grand Slam quarter-final, produced 20 more winners than her opponent but Kenin made up for that by maintaining the same gap in unforced errors.
"I'm super excited, it was a tough match," said Kenin, whose previous best show at a Grand Slam was the fourth round at Roland Garros last year.
Kenin capitalised on Jabeur's faulty groundstrokes to break early in the opening set but the Tunisian got back on serve at 3-3.
Unforced errors kept hurting Jabeur as Kenin got a second break in the next game but the Tunisian showed plenty of stomach for the fight, saving five set points over two games to keep the 14th seed waiting.
The 78th-ranked Jabeur, who said she received a call from her country's president before the match, had her opportunities in the second set but wasted three breakpoint chances in the sixth game with unforced errors.
She threw her racket away in disgust during the game which lasted close to 10 minutes.
"It was a tough moment," Kenin said. "She was playing well, I didn't know it was 10 minutes but I felt the game was pretty long. I feel like after that I got my momentum and started playing better."
Kenin was 40-0 up in Jabeur's next service game but once again the Tunisian fought back to take it to deuce before two errors on her forehand gave the American the crucial break and a 4-3 lead.
After both players held serve Kenin converted her first match point when Jabeur, 25, found the net on a service return.
Kenin will meet either world number one Ash Barty of Australia or twice Wimbledon champion Czech Petra Kvitova for a place in Saturday's final.