Serena Williams insists the prospect of matching Steffi Graf's Open Era record of 22 grand slam singles titles is not proving a hindrance as she seeks to earn a seventh Wimbledon crown.

Williams claimed her 21st slam victory 12 months ago at the All England Club, but has since given up her US, Australian and French Open trophies.

However, after beating Amra Sadikovic 6-2 6-4 on Tuesday to begin her Wimbledon defence, the top seed rejected the idea that her focus had changed.

"I think more or less about winning Australia, I think about winning the French Open. It didn't happen. I think about winning Wimbledon. I don't necessarily think about winning 22," said Williams.

While commentating on Williams' first-round match for the BBC, former world number one Lindsay Davenport suggested her fellow American had been unusually anxious against Sadikovic.

Yet the reigning champion said: "I felt I was where I needed to be. I needed to be pumped for the match. I needed to be intense. I needed to show a lot and feel a lot on the court.

"That's typically how I play. I needed to do that.

"I would be lying if I said I feel fresh, but I don't feel fatigue. I don't think I feel fresh, but I feel real hungry, super motivated, extremely ready to do the best [I can]."

Williams will face Christina McHale in round two.