Pádraig Harrington showed signs that his best golf is not far away while Shane Lowry took his best Wentworth for to the Memorial Tournament in Ohio

Playing just his fifth competitive round after 12 weeks out following neck surgery, Harrington dropped just one shot in a one-under par 71 that was good enough for a share of 26th, six shots behind David Lingmerth and Jason Dufner, who shot 65s around Muirfield Village.

Striking the ball well and putting solidly — he missed just one fairway and only five greens —  Lowry was two-under par after 11 holes before shrugging off back-to-back bogeys after bunkered approaches at the next two holes by finishing with five pars for a level par 72 for a share of 35th

Harrington opened with 12 pars but while he failed to save par after finding sand at the par-three fourth, he holed a nine footer at the fifth and a 25-footer for another birdie at the sixth before parring his way home.

Dufner and Lingmerth lead by one shot from Daniel Summerhays and Jordan Spieth with Justin Thomas and Lucas Glover a shot further back after 67s.

It was a struggle for some of the other big names with world No 1 Dustin Johnson the biggest casualty on Jack Nicklaus' speedy greens as he failed to make a birdie in a six-over 78 in which he three-putted three times and had 35 putts