Ogilvy bested U.S. Ryder Cup captain Tom Lehman, 4 and 3, at La Costa Resort & Spa.
Love had made the semifinals with a dramatic 1-up quarterfinal win over Irishman Padraig Harrington. Love holed out for eagle at the last to win that match. Johnson made the semis as he downed the last remaining No. 1 seed, Retief Goosen, by a 3 and 2 margin.
Ogilvy outdueled Englishman David Howell 1-up in 19 holes to move into the semifinal round. Lehman outlasted fellow American Chad Campbell, 1-up, in 21 holes.
Love fell 1-down to Johnson at the par-3 second after Johnson stuffed his tee shot within 3 feet of the cup and sank the birdie try. Love and Johnson had nearly the same birdie putt on the fourth, but only Love converted to even the match.
The 41-year-old Love sank a 12-foot birdie putt on the eighth to seize control of the match. Love made it two in a row as he ran in an 18-footer for birdie on nine.
'My pitching wedge has been good to me on quite a few shots the last few days. Holing that shot on 18 to get to this match, then little shots like that you hit in there close and knock the putt in,' Love said of his approach to the eighth. 'I made a couple 15-, 20-footers that were key too.'
Johnson remained 2-down as the duo halved three straight holes. Love, the 1997 PGA Championship winner, dropped his approach to eight feet at the 13th. Love converted that to go 3-up. Love drained a 20-footer for birdie on the 14th then Johnson missed from four feet closer, and he was suddenly 4-down with four to go.
Love conceded Johnson a short birdie putt at the 15th, then missed his own birdie try as his lead dipped to 3-up. Johnson, the 2004 BellSouth Classic winner, struggled on the 16th and conceded the hole and the match after missing a lengthy par putt.
'I hit the ball in the fairway a bunch and that certainly helped,' Love said. 'I'm feeling confident with the putter. Zach didn't put a whole lot of pressure on me, but he did play solid. I stayed just ahead of him.'
'When you're hitting it as good as he is, and starting to putt decent, it's a hard combination especially with a guy who has as much experience as he does,' Johnson said of Love. 'I feel good about how I played. I missed a couple putts on the back, but that was probably about it. No regrets.'
Lehman scrambled to halve the first three holes of his afternoon match with Ogilvy. The Australian sank a 6-footer for birdie on the fourth to grab a 1-up lead, and he would never look back. Lehman missed a short par putt on five and conceded the hole to Ogilvy.
Ogilvy's lead stretched to 3-up when Lehman again missed a short putt on the sixth. Ogilvy and Lehman both birdied the eighth from inside 8 feet.
Lehman made a mess of the ninth hitting his second shot well over the green and not reaching the putting surface with his third. Ogilvy meanwhile two-putted for par from 8 feet to stretch his lead to 4-up.
Ogilvy missed a makeable birdie try on 10, then Lehman had to get up and down for birdie on the par-5 11th to halve the hole.
Lehman showed some mettle. He stuck his tee shot 3 feet from the hole at the 12th and was conceded that birdie after Ogilvy could not save par from a greenside bunker.
The U.S. Ryder Cup captain dropped in a 5-foot birdie putt at the next to cut his deficit to 2-down with five holes to go. However, Ogilvy ran in a 25-footer for birdie on 13, then watched as Lehman missed a birdie putt from 18 feet.
Ogilvy led 3-up heading to 15th. Lehman again missed the putting surface, while Ogilvy left himself 12 feet for birdie. Lehman could not save par and Ogilvy lagged his birdie try to tap-in range to close out the match.
'I played nicely last week without doing anything special,' said Ogilvy. 'I had Michael Campbell in the first round, who was the last to beat me in match play, so I had a little bit of a revenge match there. Then I had another Australian, Nick O'Hern, so I had a little bit of motivation every time. This is the best I've played all week today so that's good.'
'I just didn't play well. I played poorly this morning and poorly for the first nine holes this afternoon,' Lehman said. 'But you know, Geoff played very well. You have to give him a lot of credit. He played extremely well and made a lot of clutch putts. I am proud of the way I performed this week though.'