MELBOURNE, Australia >> Everything came so easily for Iga Swiatek during a 6-1, 6-0 victory over Emma Raducanu on Saturday in the only Australian Open women’s third-round match between two past Grand Slam champions — if you thought that meant it would be close, you’d have been rather wrong — that this was how she described it:

“I felt like the ball,” Swiatek said, “is listening to me.”

Loud and clear. Asked to explain that sensation, Swiatek put her two index fingers a few inches apart and said, “It’s just being able to aim for this kind of space.” Then she spread her palms more than a foot apart to show that’s the margin for error on other days.

The difference, she said, comes down to “being more precise and actually knowing where the ball is going to go, seeing the effects that you want it to.”

When the five-time major champion and former long-time No. 1-ranked woman — now No. 2, behind Aryna Sabalenka — is at the height of her powers, as she sure has seemed to be in Week 1 at Melbourne Park, it is hard for anyone to slow Swiatek down.

The heavy-spinning, high-bouncing forehands. The squeaky-sneaker scrambling to get to every shot. The terrific returning. And so on.

Later Saturday, No. 4 Taylor Fritz, the runner-up at last year’s U.S. Open, became the highest-seeded man to leave the bracket, defeated by 38-year-old Gael Monfils 3-6, 7-5, 7-6 (1), 6-4. Monfils joined Roger Federer as the only men 38 or older to get to the fourth round in Melbourne since the field expanded to 128 players in 1988.

At the other end of the age spectrum, a pair of young Californians who have been pals for a while and trained together in the offseason — Learner Tien, 19, and Alex Michelsen, 20 — earned debuts in the fourth round at a major. Ben Shelton, who is 22, won, too. No. 1 Jannik Sinner, however, eliminated American Marcos Giron 6-3, 6-4, 6-2 and will next face No. 13 Holger Rune, who beat Miomir Kecmanovic 6-7 (5), 6-3, 4-6, 6-4, 6-4.

Tien, a qualifier ranked 121st, followed up his surprising win against No. 5 Daniil Medvedev in a five-setter that ended at 3 a.m. on Friday with a 7-6 (10), 6-3, 6-3 victory over Corentin Moutet of France. Michelsen, who is ranked 42nd, overwhelmed No. 19 seed Karen Khachanov of Russia 6-3, 7-6 (5), 6-2. It was the second time Michelsen knocked off a top-20 seed this week after beating No. 11 Stefanos Tsitsipas, the 2023 Australian Open runner-up, in the first round.

Shelton, the 21st seed and a U.S. Open semifinalist in 2023, defeated No. 16 Lorenzo Musetti of Italy 6-3, 3-6, 6-4, 7-6 (5) and will take on Monfils on Monday.

Michelsen will try to send another high seed packing when he plays No. 8 Alex de Minaur, an Australian who beat No. 31 Francisco Cerúndolo 5-7, 7-6 (3), 6-3, 6-3. Tien faces 55th-ranked Lorenzo Sonego of Italy, a 6-7 (3), 7-6 (6), 6-1, 6-2 winner over Fabian Marozsan.