PINEHURST, N.C. (AP) -- The mantra from the 66 players chasing Martin Kaymer at Pinehurst No. 2 is that anything can happen in the U.S. Open.
There is reason for hope.
Only twice in the last 20 years of the U.S. Open has the 54-hole leader managed to break par in the final round. Then again, both were runaway winners. Rory McIlroy had an eight-shot lead at rain-softened Congressional in 2011 and closed with a 69. Tiger Woods had a 10-shot lead at Pebble Beach in 2000 and closed with a 67.
Three players didn't even break 80, including Retief Goosen. He was going for back-to-back U.S. Open wins at Pinehurst No. 2 in 2005 and shot 81.
These are the five things to consider going into Sunday at Pinehurst No. 2:
BIG LEADS: Kaymer will be the first to say that no lead is safe - even the five-shot lead he takes into the final round.
He made a 10-foot birdie putt on the final hole Saturday to reach 8-under 202, and it would seem that extra shot could go a long way.
''If you're four shots, five shots, six shots, if you play a golf course like this, it can be gone very quickly,'' he said.
Dustin Johnson had a three-shot lead that was gone in two holes at Pebble Beach in 2010. Retief Goosen had a three-shot lead in 2005 at Pinehurst No. 2. And that's just over the last 10 years.
Kaymer has experience with a big lead. He led by six shots in the BMW International Open in his native Germany in 2008, and he went on to win - but only after losing the lead and having to make birdie on the first playoff hole to beat Anders Hansen.
BIG HEART: A common saying at any major, and particularly the U.S. Open, is that a player has to have a lot of heart to withstand the pressure of the final round.
Erik Compton is on his third heart.
In what is truly one of the more remarkable stories, Compton is tied for second place going into the final round after a 3-under 67 - one of only two rounds under par on Saturday - that included one eagle and five birdies.
Compton had his first heart transplant when he was 12, and still managed to play in the Walker Cup in 2001 at Sea Island. He was trying to find his way on the Nationwide Tour when he suffered a heart attack in 2007 - his heart was pumping at 15 percent capacity when he drove himself to the hospital, calling everyone to say that he loved him because he thought it was over. He had his second heart transplant six months later.
A victory Sunday - can it really happen? - would rank with Ben Hogan returning from a life-threatening car crash to win the 1950 U.S. Open at Merion.
BIG STYLE: NBC Sports analyst referred to Rickie Fowler as ''big hat, no cattle.''
In his fifth year on the PGA Tour, Fowler has heard that before. He has created a pop star following in American golf with his X-game style - bright colors, the flat bill hat, and all-orange on Sunday in honor of his college days at Oklahoma State.
He is an expert in social media - ''Rickie Fowler 2.0'' - and despite all the attention, has retained a remarkable sense of respect and consideration for VIPs and the volunteers restocking the water coolers.
But he only has one victory, just two hours down the road at Quail Hollow two years ago.
He also shot a 67 on Saturday and will be in the final group of a major for the first time. Two months ago, Fowler was only two shots out of the lead going into the last day at the Masters. He shot 73 and tied for fifth.
BIG CHASE: No one has ever come from more than seven shots behind on the last day to win the U.S. Open, and that took a regal effort. Arnold Palmer drove the first green at Cherry Hills in 1960 on his way to a 65 to win his first U.S. Open.
Only six players are under par - five of them within seven shots.
Henrik Stenson and Dustin Johnson were six shots behind, and Brandt Snedeker is seven shots back.
BIG IMPLICATIONS: What would a victory mean to Martin Kaymer?
In the last 20 years, only Woods, McIlroy, Ernie Els and John Daly have won two majors before turning 30.
Since the world ranking began in 1986, only four players have won two majors and were ranked No. 1 before turning 30 - Woods, McIlroy, Els and Seve Ballesteros.
The 29-year-old German spent about 18 months trying to build a more complete game than when he won the 2010 PGA Championship and rose to No. 1 six months later. The project is close to being completed. Kaymer won The Players Championship last month.
He was outside the top 60 just a month ago. A victory would put him just outside the top 10 - and on the way back to where he once was.