Glasson and Dan Forsman both shot a 6-under 66 to share the top spot at the second major event of the year on the Champions Tour.
Glasson has undergone surgery an amazing 25 times during his career, most of them involving his back and neck while others have dealt with repair of various tendons.
Despite those setbacks, he won seven times during a regular tour career that began in 1984.
His most recent surgery came two years ago and his game has come around this season while he has posted three Top 10 finishes.
"I always had to develop a swing around what worked," Glasson said Thursday after his solid opening round. "Whatever body part was dysfunctional, I had to leave that out and do other things.
"To me the biggest accomplishment of this whole 20-something years was that every time I came back, it was a totally new swing based on what I could do. So that in itself was kind of fun. I never got bored, that's for sure."