Serena Williams admits she has "a long way to go" to get back to her peak after being knocked out of the BNP Paribas Open by sister Venus.
The younger Williams had progressed to the third round in her first WTA Tour tournament since the 2017 Australian Open, in which she defeated Venus in the final to collect her 23rd grand slam title before taking a break to give birth to daughter Alexis Olympia.
However, Venus came out on top in Indian Wells for her 12th victory over Serena in 29 meetings, setting up a last-16 clash with Anastasija Sevastova by cruising to a 6-3 6-4 win over her sibling.
Serena said in quotes on the WTA's official website: "I haven't played in over a year.
"(Losing)'s definitely not less disappointing. I wish it were, but it's not. But then again, I wish it wasn't. Then I wouldn't be who I am.
"So I just have a long way to go, and I'm looking forward to the journey."
Serena saved three break points to hold her first service game but lost her third to love as Venus took a 4-2 lead and served out for the set in 37 minutes.
Venus then raced to a 3-0 lead in the second set after breaking her sister twice and had a match point at 5-3 which Serena saved.
Venus saved a break point of her own at 5-4 and went on to take the match.
Venus said: "(Serena's) level is super high and it was very difficult to close out the match, just getting one ball back.
"I think just I have played more matches in the last year. Even though I haven't even played that much this year, the matches in the last year count."