The victory was Agassi's first against Lendl, who had won their five previous encounters.
Lendl, the third seed, won the first set courtesy of a pair of service breaks as Agassi struggled to find his range.
However, once Agassi, seeded second, went ahead 2-0 in the second set with a break of his own he assumed complete control, adding another break in the seventh game for a 5-2 advantage before serving out the set.
The third set was dominated by Agassi, who streaked to a 5-0 lead, breaking breaking Lendl three times. He wrapped up the game in impressive style, serving four consecutive aces from 0-30 down.
However, Agassi - partnered by John McEnroe - failed to add the doubles title, losing 6-4, 6-4 in the final to Danie Visser, of South Africa, and American Pat Galbraith, of the United States.
Pete Sampras, the world No 3 who was a semi-finalist at Wimbledon, won the first clay-court tournament of his career when he defeated Alberto Mancini, 6-3,
7-5, 6-3 in the final of the Head Cup tournament in Kitzbuhel.
Karel Novacek, of Czechoslovakia, won the Dutch Open, beating Jordi Arrese, of Spain, 6-2, 6- 3, 2-6, 7-5 in the final.Reuse content