Updated

Phil Mickelson has spent so much time honing his swing for the U.S. Open that he's finding he needs to tweak his short game too.

Mickelson wound up two-putting 10 holes Thursday on his way to a 71 that left put him five strokes back of the lead at the St. Jude Classic.

"I probably spent so much time on swing and getting sharp tee to green because of the U.S. Open and the difficulty there that I'm hitting it as well as I have in quite a long time," Mickelson said. "Short game ... it hasn't been bad but today it was not good."

Davis Love III shot a 4-under 66 for his best round of the year Thursday for a share of the lead with five other players after the first round of the final event before the Open next week at Merion in Ardmore, Pa.

Stuart Appleby, Harris English, Nathan Green, Martin Flores and Glen Day also shared the lead on a day where at least three others had a piece of the top spot lead at some point. This is the first lead after any round on tour for Flores and English.

Defending champ Dustin Johnson was 5 under through six holes, taking advantage of near perfect conditions at the TPC Southwind with a temperature in the low 80s and only a slight breeze early. He Johnson finished with a 67 and was tied with 10 others including David Toms, a two-time winner here, and Shawn Stefani, who was tied for the lead before he hit into a fairway bunker and bogeyed No. 18.

Nobody could go lower than 5 under with the firm Bermuda grass greens keeping players from stopping the ball where they want, especially when chipping.

"Greens were perfect, but it seems like it's just tough to get the ball close to the hole," Toms said. "So you really have to take advantage of those shots that are shorter where you can attack. Some long shots where the ball releases and it's just tough to get it close."

This was Mickelson's first competitive round missing the cut at the Players Championship a month ago. But he was at Merion on Monday and Tuesday, and he said he feels he has a good round coming. And he also plans to use his putter rather than trying to chip from off the green.

"I hit some pathetic chips out there, then I kind of learned that you just have to putt it," Mickelson said. "I putted it from off the green and got those up and down no problem."

Brandt Snedeker, currently No. 6 in the world, opened with a 70. Boo Weekley, who won at Colonial, shot a 68 and was tied with seven others.

Love took off in February for surgery to relieve numbness and weakness caused by spinal stenosis and bone spurs. He didn't play at all in March or April, and this is his fourth tournament back on tour. He tied for 29th at Memorial last week, and tied for third here a year ago in what wound up being his best finish of 2012.

The 49-year-old Love credited his good start to being grouped with Johnson and Snedeker, who also like to play fast.

"I tried to keep up with Dustin and Brandt," Love said.

Love made the turn at 2 under and birdied Nos. 10 and 11 to move into a five-way tie at 4 under with six others a stroke back at that point. He bogeyed No. 12 and bogeyed the par-3 14th. But Love birdied two of his final three holes to finish with a piece of the lead on a day where he said he still hit some bad shots.

"I think it's rust," Love said. "I'm excited to be back, and I'm anxious and I want to play better than I'm playing. I'm a little bit tired from the two 36-hole qualifiers as well. You got to be a little bit more patient and polished. That's going to take some rounds of golf to get back."

Appleby also had his best round this year. The Australian with nine victories hasn't won since The Greenbrier Classic in 2010, and his best this year was a tie for 35th at the Heritage in South Carolina. He said he was surprised the scores weren't lower on a day where there wasn't any wind.

"I thought there were some more birdies out there," Appleby said. "I think just with the pace of the greens if you're above the hole it's tricky. I'm happy with the way I played today. Anybody who got under par today, the scoreboard, certainly fought to get there."

Notes: The six players tied for the lead is one shy of the most on tour this year. Seven shared the lead at the Wells Fargo Championship. ... Love now has six straight rounds in the 60s at this event. This is the 25th time Love has held or shared a first-round lead on tour. He has gone on to win four times, the last at the International in 2003. ... Green had the only bogey-free round of the day in his 200th start on tour. ... Paul Goydos may have re-injured his left wrist hitting out of some deep rough on 15 in his first event in more than a year after extensive surgery. He wrote on Twitter that he got some therapy after his round and planned to ice every hour but will not know how bad it is until he warms up Friday. ...Guan Tianglang, the 14-year-old from China who made the cut at the Masters, opened with a 73.