The Champions Tour's final major tournament this season is being played at the Baltimore Country Club in Timonium, Maryland, and started in flawless, sunny weather conditions.
"I feel fine," Fleisher said, despite sounding a little sick. "It's just a long golf course, a tiring golf course. You have to pace yourself."
Fleisher celebrates his 60th birthday next week.
Smyth, a two-time Champions tour winner from Ireland, played a bogey-free first round, while Blackmar's round included four birdies and two bogeys on the front nine.
He ended the day with in a 12-foot birdie putt.
At 4-under 66 are Bernard Langer, Fred Funk, Scott Hoch and Eduardo Romero, and seven others are 3-under 67, including Jay Haas and Ben Crenshaw.
Defending champion Loren Roberts shot 2-under 68, and joined four others in 15th place.