MELBOURNE, Australia -- Just as she was starting to show glimpses of returning to form, Venus Williams was let down by her serve and her concentration at crucial times and lost 2-6, 6-4, 6-4 to Ekaterina Makarova on Day 1 of the Australian Open.
The No. 22-seeded Makarova upset Serena Williams in the fourth round here in 2012 but was comprehensively outplayed in the first set Monday, dropping serve three times.
For her part, Serena appeared as polished as ever in beating Australian teenager Ashleigh Barty. The top-ranked Williams won her 23rd consecutive match -- including 18 at the end of last season and four last week in winning the Brisbane International -- after beating Barty 6-2, 6-1 in 57 minutes.
Venus Williams had chances in the second set, missing a break-point opportunity to go up 4-2, and then serving three consecutive double-faults after leading the ninth game 40-30 to surrender a crucial break.
The 33-year-old Williams, the second-oldest player in the tournament and seven-time Slam champion, took some time out after the second set to change her zebra-striped dress and came back strongly, taking a 3-0 lead. But Makarova rallied again, and Williams' error count rose -- she had 21 of her 56 unforced errors in the deciding set.
Williams has struggled with injuries and illness in recent seasons, but she reached the final of the WTA event at Auckland to open the year and said after arriving at Melbourne Park that she was feeling better than she had in years.
"The last 12 months I have had issues, but this year I definitely am looking forward to having a good run and feeling well," Venus said.
That didn't happen Monday.
"My level was a little bit too up-and-down. Obviously my error count was a little high," she said. "I have to give her a lot of credit, though, she was very determined, played hard."
It was only the second time in 14 appearances that Williams lost in the first round at the Australian Open, where her best run remains a loss to her sister in the 2003 final.
"It was a really tough match to play someone like Venus in the first round, she is such a great player," Makarova said. "At 3-0 down [in the final set], I decided I had to fight for every point. I just kept fighting, and I turned around the match."
Contrastly, Serena Williams continues to be in rarefied territory. Her Brisbane title was the 58th of her career -- she won 11 last year, including the French Open and US Open. A five-time winner of the Australian Open, she's trying to end Victoria Azarenka's two-year run as women's champion.
"Obviously I'd love to win again in Melbourne," Williams said.
"This is one of those matches where you're just happy you got through it," said the power-hitting 18-year-old, who is seen as one of the rising stars in U.S. tennis.
Keys, ranked 36th, had a breakthrough season in 2013, which she started ranked 137th. She reached the third round at last year's Australian Open, which she entered as a wild card, and Wimbledon. Keys will face Zheng Jie of China in the second round.
Makarova will meet another American in the second round after Falconi beat Anabel Medina Garrigues of Spain 6-3, 6-1. No. 7 Sara Errani, the 2012 French Open finalist, was beaten 6-3, 6-2 by Julia Goerges of Germany, and No. 12 Roberta Vinci lost 6-4, 6-3 to Jie.
"Like zero, you know," Li said when asked what she knew about Konjuh's game ahead of the match. "I tried to find her game in YouTube, and I watched a couple of games. But it was still strange at the beginning of the match because I really didn't know the way she played on the court."
Konjuh is the defending Australian Open and US Open junior champion.
Li, who lost in the final to Azarenka last year and Kim Clijsters in 2011, has advanced to at least the fourth round every year since 2010.
"This is my favorite Grand Slam,'' Li said. "Always looking forward to come back to Melbourne.''
On Monday, Li frequently strayed from her traditional baseline position, several times volleying from the center of the court for winners during the fourth game of the second set, when she broke Konjuh's service.
Li will spend her off day Tuesday studying any available video on qualifier Belinda Bencic of Switzerland, the reigning French Open and Wimbledon junior champion who beat 43-year-old Kimiko Date-Krumm of Japan in three sets earlier Monday. Date-Krumm is 27 years older than Bencic, the reigning French Open and Wimbledon junior champion.
Other winners were Wimbledon semifinalist Kirsten Flipkens, beating Britain's Laura Robson, No. 9 Angelique Kerber, 2011 US Open champion Samantha Stosur, No. 14 Ana Ivanovic, No. 26 Lucie Safarova, No. 28 Flavia Pennetta, No. 30 Eugenie Bouchard and No. 31 Daniela Hantuchova.
Stosur is trying to improve on a mediocre record at her home Grand Slam -- she has never advanced past the fourth round at Melbourne Park and was eliminated in the second round in 2012 and the first round last year.
She has spoken of the pressure of local expectations and why she's never fared well in many other tournaments in Australia, including the recent Hopman Cup, where she lost all three matches in the round-robin tournament.