Three rounds are almost complete at the 2018 PGA Championship, and an exciting finish awaits at Bellerive.
After birdieing five of his first eight holes and playing the front side in 31 strokes, Woods stalled on the back nine, failing to convert any birdie opportunities and squandering a lovely chance at the par-5 17th, where he three-putted for par.
At the par-5 8th hole, Woods had to lay up with his second shot but hit a great approach.
In stark contrast, the 132-yard third hole played to an average of just 2.563 thanks to a favourable front pin position which saw 55 birdies and no bogeys from the morning starters.
Woods, whose earlier charge on the easier front nine raised the massive gallery's excitement to fever pitch, was among a logjam of six trailing by four shots.
Spieth had just made birdie at the par-3 16th when he faced his tee shot into the creek running along the next hole.
Woodland took a one-stroke lead into the day after shooting a 64 Thursday and chipped his way to a birdie on his second hole Friday, No. 11.
"The golf course is good", said Woodland, a three-time PGA Tour victor who has never finished among the top 10 in a major championship.
Finau began this wild ride Friday afternoon with five straight birdies, four of them from between 20 and 25 feet, the shortest one at 12 feet. From well right of the 12th fairway, he tried to hit through a gap and instead caromed off a tree and out-of-bounds, leading to triple bogey and falling back to 4 under for the tournament.
Players making the cut but finishing below 70th place will be paid in diminishing increments of $100 each ($19,500; $19,400; etc.). If you do that well, and, obviously, in there you're going to make those putts. I said to my caddie a couple of holes before it was the most fun I'd ever had and then that happened. Woodland is among the most powerful players in golf.
"That self-belief has to come out and I feel like the last six to eight weeks has been a real positive for me".
Woods, a 14-time major victor in the eighth month of his comeback from spinal fusion surgery, opened Saturday with a birdie at the par-5 eighth.
Spieth's next shot at the career Grand Slam comes next May at Bethpage Black.
Tiger Woods, who won his 14th major in 2008, shot 66 to end on eight under. "There were good signs that carried over to today, and hopefully tomorrow it gets better and better".