Hmmm. Better read again. They are talking about the same event.
As also the high priest doth bear me witness, and all the estate of the elders: from whom also I received letters unto the brethren, and journeyed to Damascus to bring them also that were there unto Jerusalem in bonds to be punished.
Acts 22 : 5
And it came to pass, that, as I made my journey, and drew nigh unto Damascus, about noon, suddenly there shone from heaven a great light round about me.
Acts 22 : 6
And I fell unto the ground, and heard a voice saying unto me, Saul, Saul, why persecutest thou me?
Acts 22 : 7
And I answered, Who art thou, Lord? And he said unto me, I am Jesus of Nazareth, whom thou persecutest.
Acts 22 : 8
And they that were with me beheld indeed the light, but they heard not the voice of him that spake to me.
Acts 22 : 9
These are speaking of the same event, Paul's conversion. Both written by Luke, in Acts.