First round leaderboard (US unless stated):
-7 L Westwood (Eng) -6 C Wittenberg -5 P Harrington (Ire) -4 T Petrovic, J Williamson, DJ Trahan, G Willis, M Connell, B Estes, J Senden (Aus)
Selected others: -1 R McIlroy (NI), G Owen (Eng) level I Poulter (Eng)
It was the first time world number three Westwood had played in Memphis
Lee Westwood continued his fine form by posting a course-record 63 at TPC Southwind to take an early clubhouse lead at the St Jude Classic in Memphis.
The world number three's seven-under opening round secured a one-shot lead over over American Casey Wittenberg.
Ireland's Padraig Harrington was back in third following an excellent 65.
"It could have been better but I'm not going to cry too much from missing from four feet on the last. I can't be disappointed with that," said Westwood.
The Englishman, who played next week's US Open venue Pebble Beach on Sunday and Monday ahead of the second major of the year, certainly hit the ground running in Memphis.
He went out in 29 for his opening nine holes and ultimately went bogey-free with five birdies and an eagle, while the only blemish was a missed birdie putt at the ninth, his last.
"It's been a long time since I played a course for the first time," Westwood added.
"I just played the Honda for the first time this year. I finished in the top 10. That was pretty good.
"Last year we all played the course at Dubai for the first time there. I was 23 under. I adjust fairly well, I think."
England's Ian Poulter was three under par after 10 holes, but the world number five had five bogeys in his final seven holes in humid conditions with the temperature touching 38C (100F) to drop to a two-over 72.
Fellow Englishman Greg Owen and Northern Ireland's Rory McIlroy had solid rounds, to card one-under-par 69s.