Fourth-seeded Safina coasted to a 6-1, 6-3 win over fifth-seeded Kuznetsova in a match that lasted 1 hour and 18 minutes at Ariake Colosseum.
"I've played the best tennis this week I've ever played,'' said Safina, who will move up to No. 3 in the world rankings. "It's always nice to move up in the rankings and hopefully I can keep improving.''
Safina broke Kuznetsova with a crosscourt forehand from the baseline to go up 3-2 in the second set.
She broke Kuznetsova for the third time in the final game, winning the match when her opponent's forehand volley went wide.
Safina has also won this year in Los Angeles, Montreal and Berlin and is now tied with current No. 1 Serena Williams for the most titles in 2008.
It was the 10th meeting between the two Russians. Safina now has six wins against four losses.
Former U.S. Open champion Kuznetsova was bidding for her first title of 2008.
Player Ratings: Barcelona 3-1 Sporting
Kuznetsova reaches final at Pan Pacific Open
Kuznetsova, Safina in final at Pan Pacific Open
