Sergei Filin, who suffered severe burns to his face and damage to his sight, spoke of a "terrifying pain".
Pavel Dmitrichenko has denied arranging the assault in a case that revealed bitter infighting at the Bolshoi.
Two other men are being tried with him over the attack in January.
Mr Filin, 43, began his testimony on Wednesday by saying he was fair and transparent in distributing roles.
But he said that Mr Dmitrichenko, 29, kept trying to find compromising material on him.
He described the night of the assault, and how his attacker said "Here's a greeting for you" as he threw sulphuric acid in his face.
"Suddenly I felt liquid, I felt a sudden pain, I had never experienced such pain," he said.
"Terrifying pain, my eyes couldn't see."
Mr Filin's highly anticipated court appearance came despite doctors' orders for him to avoid stress, according to AFP news agency.
Prosecutors say Mr Dmitrichenko colluded with ex-convict Yuri Zarutsky, who has admitted throwing the acid at the ballet chief outside his home. Mr Zarutsky insists he acted alone.
A third defendant, Andrei Lipatov, who is accused of driving the car used to transport the alleged attacker, has denied any part in the attack.
If convicted, the three accused could be sentenced to up to 12 years in prison.
Mr Dmitrichenko has been in custody since his arrest in March.
Meanwhile, Mr Filin has undergone more than 20 operations on his eyes since the attack.
Doctors in Germany have managed to partially restore his sight, but he will reportedly need further treatment.
He was once star of Russia's renowned Bolshoi theatre, and in 2011 became the artistic director of the ballet troupe.
The acid attack exposed vicious internal rivalries which eventually caused the dismissal of Bolshoi director Anatoly Iksanov.
The artistic director of Russia's Bolshoi ballet has described having acid thrown in his face during the trial of a dancer accused of ordering the attack.