Becker, without a tournament win on clay in his illustrious career, was frustrated again in a 6-1, 5-7, 7-5 defeat by Spain's Alex Corretja, ranked No 44 in the world.
Edberg, who like Becker has won every Grand Slam except the French Open, slipped to a 6-4, 7-5 defeat by Jaime Yzaga, his second defeat by the Peruvian within a week following last week's Madrid Open.
With the third seed, Goran Ivanisevic, also going out 7-6, 6-0 to the Russian Yevgeny Kafelnikov, Stich has a superb chance of retaining the trophy.
He won twice yesterday, battling back from one set down to finish off his rain-delayed second-round match against Spain's Emilio Sanchez 6-7,
6-3, 6-4. A few hours later he beat the Russian Andrei Chesnokov 6-0, 6-4 to reach the quarter-finals.Reuse content