Serena Williams motored into the third round at Wimbledon on a day when both Caroline Wozniacki and Victoria Azarenka crashed out.
Williams believes her performance level is heading in the right direction after moving through to the third round of Wimbledon.
The seven-time champion made her first playing return to Centre Court since 2016 and eased past Bulgarian Viktoriya Tomova 6-1 6-4.
Williams is still working her way back up to full speed following the birth of her daughter last year, but is already looking a threat at the tournament.
"There's so many things that I want to improve on, but that's kind of how I always feel," she said.
"I feel like I'm going in the right direction. This match was better than my first round. I just hope every match is better.
"I served a little more consistent. I still want to work on getting my first serves in more. Overall it's definitely a little bit better than the first round."
Second seed Caroline Wozniacki became the highest-ranked casualty of the tournament so far as she lost to Ekaterina Makarova.
The Dane, who won the title in Eastbourne last week, lost 6-4 1-6 7-5 to the Russian on Court One, meaning half of the top 10 seeds have already been dumped out in the opening two rounds.
Wozniacki, who was also troubled by flying ants, said: "I think I did everything I could. I fought as hard as I could. I can't even be mad at myself because I played up to the level that I can.
"I think she played above her level and really raised it and got a little lucky and played well when she needed to."
Karolina Pliskova is enjoying playing without pressure as she reached the third round for the first time. The Czech won the battle between former world number ones against Victoria Azarenka on Centre Court.
She was seeded second in 2017 but succumbed amid high expectations and crashed out in the second round that time.
She said: "This year I tried to not put that much pressure because last year I think I put too much.
"Everybody thought maybe I'm going to win. The pressure was a little bit bigger."
Venus Williams overcame a scare to book her place in the third round.
The 2017 runner-up and five-time former champion came from a set down to beat Alexandra Dulgheru 4-6 6-0 6-1. She was sloppy in losing the opening set but got her act together.
Madison Keys celebrated Independence Day by beating Thailand's Luksika Kumkhum as she recorded a 6-4 6-3 victory but British hope Katie Swan's run was emphatically ended by 29th seed Mihaela Buzarnescu.
Croatian Donna Vekic followed up her toppling of fourth seed Sloane Stephens with a 7-5 6-4 win over Rebecca Peterson while Agnieszka Radwanska went out to Lucie Safarova.