Luke Donald and Justin Rose were among the leaders after day one of the Jack Nicklaus-hosted Memorial tournament in Dublin, Ohio.
Australian Matthew Goggin topped the leaderboard after his seven-under par first round of 65.
Kenny Perry and Jerry Kelly of the US finished at six-under par, while their countryman Brett Quigley and another Aussie, Rod Pampling, were two shots back at five-under.
Rose and Donald followed at four-under - in a group also including Swede Carl Pettersson, as well as Matt Kuchar and Nick Watney of the US - after both going round in 68.
Responding to comments made by Jack Nicklaus - who hosts the Memorial tournament – questioning the importance of the upcoming Ryder Cup, Rose said: "There are a lot of guys trying to play great golf to get into the Ryder Cup"
"It's like a six-month run where everyone is quite intense about the whole thing, so it's a big deal."
Golfing legend Nicklaus had labelled the US v Europe contest as 'goodwill event for bragging rights'.
Luke Donald and Justin Rose were among the leaders after day one of the Jack Nicklaus-hosted Memorial tournament in Dublin, Ohio.
