Mickelson was 23 when he won the winners-only Mercedes Championships in 1994, beating Fred Couples in a playoff. He won again in 1998, the final year the Mercedes was held at La Costa, by holding off Tiger Woods and Mark O'Meara.
But the Accenture Match Play Championship has not been as kind, part of that due to the fact anything can happen over 18 holes of match play.
He twice was eliminated in the first round, lost in the third round three other times and saw his best chance frittered away in 2004 when he made bogey on the par-5 18th hole to lose to Davis Love III in the quarterfinals.
Is it frustrating?
'I would say so, yeah,' he said. 'I love the golf course. I love coming out here, because it brings back so many great memories.'
Some of them are from his victories, but Lefty also saw La Costa from behind the ropes as a teenager, watching with his father as players like Tom Watson, Lee Trevino and Lanny Wadkins competed in the Mercedes.
But he is good enough that a few victories might take him a long way.
'I had a very good chance when I lost to Davis,' he said. 'I was playing well in 2004. I had a couple of wins, and I ended up losing on the last hole. That was the year I could have gone quite far.'
He made it to the third round with relative ease Thursday. Mickelson built a 2-up lead on John Daly after six holes and had control until hitting his approach into the water on the par-5 eighth, and Daly squared the match with a birdie on the ninth. Mickelson made eagle on the 11th to regain the lead, and pulled away.
Next up is David Howell of England, who has never played against Lefty.
'He's a great player, isn't he?' Howell said. 'I'm just going to have to shoot a good score.'
Friday could be a rubber match of sorts between Padraig Harrington and Vijay Singh.
Harrington can't recall facing the big Fijian in match play, but he does remember two playoffs against him. Singh won the Malaysian Open five years ago, beating the Irishman in a playoff. Last year, Singh missed a 30-inch putt in a playoff at the Honda Classic to lose to Harrington.
'Hopefully, I want to play a little better than I did today,' Harrington said.
He was 3 over for his round and two holes down to Angel Cabrera when Harrington birdied the 16th and 17th to square the match, then halved the 18th hole with birdies.
He won on the first extra hole when Cabrera caught a tough lie in the bunker.
'I haven't got a consistent swing,' Harrington said. 'I haven't got a consistent anything.'
Tiger Woods will play the third round against Chad Campbell, whose career took a turn for the better thanks to the No. 1 player.
Campbell grew up in west Texas and played at Midland College for two years, doing well enough to attract attention from NCAA Division I programs. Among the schools interested was Nevada-Las Vegas, but it only had one scholarship left and was recruiting a top junior from California -- Woods.
Woods had narrowed his choice to Stanford and UNLV before opting for the Cardinal. With a scholarship available, Campbell headed for Las Vegas.
Asked if Campbell ever thanked him for going to Stanford, Woods laughed and said, 'No.'
But he knows Campbell well.
'He drives it great, hits his irons really well,' Woods said. 'When he gets that putter rolling, he can really put up some good numbers.'
There was an ominous sign Thursday, when Campbell played in the match behind Woods and won the 18th hole for a 1-up victory over Henrik Stenson.
'The times I saw him back there,' Woods said, 'he was in the fairway.'
Geoff Ogilvy is carrying a couple of banners at La Costa. He is the only player making his debut at the Match Play Championship who is still playing, and the only Australian out of the 10 who started in the 64-man field. ... With Rory Sabbatini having been eliminated in the first round, Chad Campbell is the only player who can win a $500,000 bonus for capturing the West Coast Swing. His only hope is to win the tournament. ... Eight of the 16 players remaining are from the United States, which started with a career-low 25 players in the field. Europe, which started with 17 players, is down to Luke Donald, Padraig Harrington and David Howell.