Henin-Hardenne was in a class of her own against world number 25 Dokic, winning her eighth tournament in 17 this year.
The U.S. and French Open champion missed out on the number one spot when she lost to Clijsters in the Filderstadt Grand Prix last weekend but made no mistake on Sunday to become the second Belgian to hold the top spot.
"It is just an amazing feeling," she said. "Now I am number one in the world it is just amazing because I did everything I could and it is a real achievement.
"I don't realise right now that I am the 13th player on the WTA Tour to be number one. Tomorrow is going to be easier. Today I just tried to stay focused on the match and whatever I had to do was working good.
"I served unbelievably, like I never have in the past. You could finally see today the work I did in the last few months on my serve and that is so important because you can win easy points and gain so much confidence."
Dokic, who had shown much improved form to defeat Clijsters in the semi-finals, lost her opening service game to 15 and earned just three more points in the set after that.
Henin-Hardenne wrapped up the first set in 15 minutes, slamming down aces and dominating the net.
Dokic opened the second set by winning her first point in nine and went on to win the game with the help of a firm smash and some more confident groundstrokes.
She then took Henin-Hardenne to deuce and showed the battling qualities she had displayed in earlier rounds, but squandered three break points. Henin-Hardenne held on to win the game with a crisp volley.
The Belgian, with the prospect of the number one spot spurring her on, never looked in trouble and she secured the win when Dokic hit long.
"She served better than me and she was more solid than me," said Dokic, who was in tears on court as she thanked her coach following a dismal slump over the past year.
"I was not there. I was too passive, I didn't go for my shots. I just tried to make them and she took advantage of that," she said.
