The top of the Masters leaderboard features a smattering of golf's most experienced players.
Lee Westwood became the first player to reach five under par, and he made the turn to the back nine one shot ahead of Paul Casey.
The 47-year-old Westwood and 43-year-old Casey have had top-10 finishes at each of the four majors, but neither have come away with a title.
The last golfer to win his first major championship is far away from the leaders at Augusta National Golf Club.
Bryson DeChambeau went through a litany of errors on the back nine to start his first tournament as a major champion.