Steve Stricker, Duffy Waldorf co-lead senior major at Firestone

(Photo credit: Jeff Lange / USA TODAY NETWORK)

Defending champion Steve Stricker is tied with Duffy Waldorf atop the leaderboard at the Kaulig Companies Championship after Thursday's first round at Firestone Country Club in Akron, Ohio.

At the major previously known as the Senior Players Championship, Stricker and Waldorf fired matching rounds of 4-under 66. They established a one-shot lead over Kenny Perry and Australia