However, according to the Washington Independent newspaper and the Afghan news service Pajhwok, Karzai's main rival, Abdullah Abdullah, said all of Afghanistan was awaiting a change for the better.
"All citizens are awaiting change and their votes won't go in vain. I'm optimistic the final outcome will be as good as the initial one," remarked the former foreign minister.
The Abdullah camp has said recently that it will not accept a Karzai victory as a legitimate outcome.
"A large number of our countrymen could not vote due to insecurity. This reflects the seven-year-old government's failure," observed the ex-minister.
Karzai and Abdullah Abdullah's separate claims of victory came a day after officials said there was a historic 50 percent voter turnout, notwithstanding violence in the southern and northern parts of the country.
Despite a huge military presence, the day saw militants wantonly attempting to disrupt the polls even as some 300,000 Afghan and international troops patrolled trying to prevent the attacks.
The election followed a lively campaign period in which dozens of candidates are vying for the presidency.