MEMPHIS (Tennessee) • Phil Mickelson was one over after three holes in the third round of the WGC-St Jude Invitational on Saturday, but still felt inspired to send his brother and caddie a positive message.

"On the fourth tee I said to Tim, 'This is so much fun'," he said. "I'm having so much fun because I can feel my game turn around.

"I'm starting to play well again. I'm starting to putt well and starting to drive the ball well... I just think the results are going to start to slowly come back."

The results came back rather quickly as Mickelson shot a four-under 66 to move up to tied-sixth at seven-under 203 overall, five strokes behind leader and fellow American Brendon Todd (69) heading into the final round in Memphis.

This is the highest on the leaderboard a player aged 50 or over has been after 54 holes of a WGC event since Spain's Miguel Angel Jimenez at the 2014 Mexico tournament.

While he remains an outside bet to win his first PGA Tour tournament since February last year at Pebble Beach, the five-time Major champion feels he is building some momentum ahead of Thursday's PGA Championship - the year's first Major - at TPC Harding Park in San Francisco.

"I'm going to have to shoot something really low, probably 63, 64 to have a realistic chance," the 50-year-old said.

"It's certainly out there, I've shot it before, but good test of golf."

He has just one top-10 finish in 13 Tour starts this season, but TPC Southwind has always offered him low-scoring opportunities.

He has not finished lower than 12th between 2013 and 2018, when he was second twice and third once.

And having made the cut in his three previous events, "Lefty" is hoping to gather a head of steam with a sixth Major in mind.

"I've had a little bit more consistency the last few weeks and this has been a good week so far," he added. "It's exciting that I'm starting to play well as we head into them."

AGENCE FRANCE-PRESSE