LONDON - Whether it was the swathes of empty seats to greet her arrival or her sluggish movement and frequently misdirected groundstrokes, there was little in Petra Kvitova's first round victory to suggest she was the defending Wimbledon champion.

In contrast to number one seed Maria Sharapova, who treated a packed Center Court to a regal display on Monday, the Czech showed little superstar quality as she nervously moved into the second round with a 6-4 6-4 win over Uzbekistan's Akgul Amanmuradova.

It is 12 months since the number four seed upset Sharapova to claim the title, but she looked ill-at-ease in the role of champion as she strolled out on Tuesday to begin her title defence.

It ended happily with the Czech saluting Centre Court with a smile and a wave, but it began in a flurry of unforced errors.

Petra Kvitova of the Czech Republic celebrates after defeating Akgul Amanmuradova of Uzbekistan in their women's singles tennis match at the Wimbledon tennis championships in London June 26, 2012.[Photo/Agencies]

"I was nervous," she said during a rather swift press conference that extended to just three questions.

"It was first time for me to be as the defending champion of the Grand Slam. It was huge honor to come to the Center Court.

"Of course I would like to make everyone happy, but it's not that easy."

She looked less than happy in the opening games as she was broken early by the world number 96 and was twice just one point away from falling a double break behind.

There was a hint of ruthless arrogance in the way Sharapova dispatched Anastasia Rodionova, but Kvitova was edgy and almost diffident.

Her movement was poor and the mistakes were multiplying, but her superior power meant an upset never felt likely providing she could find her range.

At 4-1 down in the first set she finally started to put it all together and she won five games in a row to win the opening set and the second was more straightforward.

A rain delay threatened to cause the first appearance of the Wimbledon roof, but the giant mechanical structure was held back as the swift shower passed and Kvitova returned to court to finish off her opponent.  

"It was lot of firsts for me today but I'm happy that I stayed calm inside and not to be panic in the important points," she said.

Next up for Kvitova is a second round clash against Britain's Elena Baltacha or Italy's Karin Knapp.