MELBOURNE, Australia -- After an uncommonly difficult beginning that featured two wins against former top-10 players, Serena Williams enjoyed a leisurely Saturday stroll into the fourth round of the Australian Open.
The No. 2 seed dismantled fellow American Nicole Gibbs 6-1, 6-3 in a breezy 63 minutes.
"It's such a beautiful day today; it wasn't really hot," Williams said in her on-court interview. "It was really good to get this under my belt."
Williams, similar to her first-round match against Belinda Bencic, got a little nervous at the end when she was serving for the match and saw Gibbs break her serve for the first and only time.
Williams, 35, has now won 39 of her 41 matches against players from the United States who are younger than she is. Gibbs, 23, was only 2 years old when Williams entered her first WTA event, in 1995 at Quebec City. Gibbs was attempting to reach her first fourth round at a Grand Slam.
"She makes the court feel very, very small," Gibbs said. "I was definitely feeling a lot of tension from early on in the match ,and it was showing in my serve and my forehand. I was catching the net a lot -- the net felt 10 feet high today."
Next up for Williams: No. 16 seed Barbora Strycova, who defeated No. 21 seed Caroline Garcia 6-2, 7-5. In their two previous matches, Williams scored straight-sets wins against Strycova, both at majors in 2012.
"I saw her play in Sydney," Serena said of Strycova. "She's super fit. She has a good game. She's very aggressive, so that would be nice to play.
"I don't have anything to prove in this tournament here. Just, you know, doing the best I can. Obviously, I'm here for one reason. But at the end of the day, this is all bonus for me, and I look forward to playing her. I'm ready for her."
Williams is a six-time Australian Open champion, matching Novak Djokovic for the Open era record. To regain her No. 1 ranking, she must win the title here and hope Angelique Kerber loses before the final.
Another American, Jennifer Brady, is certifiably the longest of shots to reach the second week of the Australian Open.
The 21-year-old native of Harrisburg, Pennsylvania, is ranked No. 116 among WTA players and to this early point in her career has won $175,000 in prize money. If Brady can win Monday's fourth-round match, she will bank $440,000.
Brady continued her dazzling run Saturday, defeating No. 14 seed Elena Vesnina 7-6 (4), 6-2. Including three qualifying matches, she has won six straight here at Melbourne Park.
"It feels amazing," Brady said. "I mean, coming here, being in the qualifying, I didn't expect to make it all the way until second week. One of my goals, actually, was in the next couple years to be playing in the second week of a Grand Slam. I sat down and had that discussion with my coaches and the rest of my team a couple of months ago.
"I wrote it down. I said it, but I didn't say it confidently."
This is Brady's main-draw debut in a Grand Slam after failing to qualify five previous times. More context: Brady came into this event with exactly two WTA-level victories, both achieved in Guangzhou, China, last fall.
In one of the most entertaining matches here so far, Brady saved five match points and defeated Heather Watson 10-8 in the third set to advance to the third round.
Brady is the 17th-ranked American woman, but she also was one of only five U.S. players still alive when her match ended Saturday. That was reduced to four when Gibbs lost.
"Usually," Brady said, "I'm just there the first couple of days, and it's pretty hectic. It's actually pretty nice [now]. The cafe is not so crowded."
Brady's fourth-round opponent will be another surprise contender: Mirjana Lucic-Baroni, who came back to defeat Maria Sakkari 3-6, 6-2, 6-3 on Saturday.
The WTA's No. 79 player, Lucic-Baroni won a first-round singles match here in 1998 and then went 19 years before collecting her second, a three-set win over Chinese qualifier Qiang Wang. Sakkari was 2 years old when Lucic-Baroni got that first win at Melbourne Park.
In the second round, Lucic-Baroni surprised No. 3 Agnieszka Radwanska, and now here she is in the fourth round, equaling her more recent breakthrough performance at the 2014 US Open.
Back in 1999, Lucic-Baroni was a semifinalist at Wimbledon, losing there to Steffi Graf. The 34-year-old Croatian, who suffered a series of personal setbacks, was absent from Grand Slam play from 2004 to 2009.
In other action, US Open runner-up Karolina Pliskova rallied from 5-1 down in the third set to beat Jelena Ostapenko 4-6, 6-0, 10-8 and reach the fourth round for the first time.
Ostapenko twice served for the match and twice she was broken, winning only one point in each game.
She saved a match point before holding in the 12th game, prolonging the match for another six games until fifth-seeded Pliskova finally broke serve again.
Also, No. 6 seed Dominika Cibulkova was upset by No. 30 Ekaterina Makarova 6-2, 6-7 (3), 6-3. That meant the No. 3, No. 4 and No. 6 seeds on the women's side were all gone by the fourth round.
Makarova moves on to face Johanna Konta, who breezed past former No. 1 Caroline Wozniacki 6-3, 6-1. Makarova and Konta also met in the fourth round last year, when Konta won 4-6, 6-4, 8-6 and went on to make a surprise run to the semifinals.
"We played [in the] fourth round last year, and we had an incredibly close one,'' Konta said. "I'm ready for a battle, and it will be nothing short of that."
No. 22 Daria Gavrilova beat 12th-seeed Timea Bacsinszky 6-3, 5-7, 6-4.
The Associated Press contributed to this report.