Woods unleashed a wild swing to cut it from left to right, avoiding the trees and bending towards the pin at Club de Golf Chapultepec in Mexico City.
It was similar to what we saw from Woods in a T-15 finish at last week's Genesis Open, and he's poised for his best result in three starts this season as he walked off the course T-10.
Johnson kickstarted his round with an eagle at the par-four second, where he hit his tee shot to four feet.
Kuchar on Saturday stumbled to a 79 - he had five bogeys and three double bogeys on his card - while playing in the final group with Johnson and McIlroy.More news: Manchester United vs Liverpool, Premier League
Dustin Johnson was cruising along Saturday in the Mexico Championship until one swing put him in a bad spot, and the next shot made it even worse. The next birdie came hours later at the par-3 13th hole, where Woods stuck the approach inside five feet from 221 yards.
"I'm driving it well, really controlling distance with the irons".
"The ball was sitting down just enough where I didn't think I could clear that tree", he said.
A sixth birdie in seven holes took McIlroy to 17 under and within four of the lead heading to the last, where he three-putted from the fringe for a closing bogey to increase Johnson's winning margin.
Fox hit just 10 of 18 greens in regulation during his final round to finish on 11 over in a tie for 67th. He missed from 4 feet at the 12th - and had to make a 4-footer for par, before converting a 5-footer at the 13th for his final birdie.