Serena Williams says she is getting closer to being back to her best ahead of the Wimbledon quarter-finals.
The seven-time champion faces Italian world number 52 Camila Giorgi for a place in the last four in only her fourth tournament since giving birth to daughter Olympia in September.
After sweeping aside Russian Evgeniya Rodina 6-2 6-2 on Centre Court, Williams, 36, had an ominous warning for her rivals.
She said: "I feel like I'm getting to where I want to be.
"For me, there's so much further I want to go to get back where I was, and hopefully go beyond that.
"I'm getting there. I don't think I'm there yet. I feel like it takes time to get there.
"I'm always striving for perfection. There's a lot of things that, I don't know if you can tell, but I really need to work on. Hopefully, I can get there."
Williams, currently the world number 181 having slipped down the rankings following her maternity leave, is the lowest-ranked player to reach the Wimbledon quarter-finals in the open era.
Seventh seed Karolina Pliskova's defeat to Kiki Bertens means that none of the top eight are in the quarter-finals for the first time since the All England Club introduced seedings in 1927.