The 31-year-old Swede mercilessly exposed the limitations of the 21-year- old from Minsk as he reversed a 21-6, 21-7 defeat by Samsonov in the team event last week.
After sealing his 21-12, 21-17, 21-13 victory with a winning smash through Samsonov's backhand, Waldner collapsed on the court in disbelief at what he had achieved.
Waldner, the second seed, who lost in the men's doubles final earlier in the day, was appearing in his fourth world singles final. He was defeated in the title matches in 1987 and 1991 before taking his first title in 1989.
Samsonov, seeded joint third, had defeated the reigning champion and top seed Kong Linghui, of China, in Sunday's semi-finals but, fine prospect though he is, he was made to look distinctly ordinary by the vastly more experienced Swede.
Waldner, when asked to compare his two world titles, said: "I think the first time you win a big tournament is the best feeling. But it is eight years since I won and that is a long time. Today I remembered how good it can feel to win."
Waldner said playing an individual singles final was very different from a team event.
"Against Belarussia, even if I lost, we would win because we have a better team." he said. "I didn't play very well then but playing best- of-five matches is different. My only chance today was to put that defeat out of my mind, and also to forget about the doubles we lost earlier today."
Waldner said he felt that a small adjustment he made to his serve and his ability to attack Samsonov with his forehand were the keys to his victory.
He won countless points with rapier forehand drives down the line that the German-based Samsonov could not handle.
Each game was a procession. Waldner went ahead 4-3 in the first and was never headed. He never trailed at all in the second. And once he moved in front, 4-3 in the third, he was there to stay, although Samsonov recovered from 12-6 to 14-11 before Waldner cut his rally short.
In the women's final, the Olympic champion Deng Yaping stepped up a gear after losing the opening game and overwhelmed her fellow Chinese Wang Nan 12-21, 21-8, 21-11, 21-10 to retain her world title.
The stocky 24-year-old Deng had too much guile for her 19-year-old rival and once she made the necessary improvement after the opening game, it was one-way traffic and she went on to underline her reputation as the foremost female player of the modern era.
Deng began slowly and tentatively and Wang had plenty of time to play her shots as she rolled to the opening game.
But Deng increased the pressure and it was too much for Wang, the champion racing to victory in just under an hour.