BETHESDA, Md. (AP) - The Rory McIlroy chase is on.
The third round of the U.S. Open got under way Saturday at hot, humid, breezy Congressional, with Webb Simpson making five birdies over his first 10 holes. He was still 10 shots behind McIlroy. The second-place player, Y.E. Yang, was six back.
McIlroy entered the weekend at 11-under 131, a record 36-hole score at the U.S. Open. The six-stroke lead matched a U.S. Open record for the biggest advantage at the halfway point.
Tiger Woods was up six at Pebble Beach en route to his 15-stroke blowout at the 2000 U.S. Open and some were saying McIlroy's performance, at least after two rounds, is every bit as impressive.
"It's very near the best I can play," McIlroy said.
Before the leaders got on the course, the most talked-about round of golf in the Beltway was going on a few miles away: President Barack Obama and House Speaker John Boehner teed it up in the early morning at Andrews Air Force Base - a little politics on the links.
Around the time they were to finish, McIlroy was scheduled to be warming up at Congressional for a late-afternoon tee time.
McIlroy would have come into Saturday's play with an even bigger lead had he not slipped up on the 18th hole Friday, hitting his drive left, then losing control of the recovery shot and knocking that into the water. He ended up with double bogey. It may have offered a ray of hope - but only a small one - to the 71 players who returned for the weekend to chase him.
"It's only two days," said Zach Johnson, who at 2-under par was in a five-way tie for third place. "I'm not going to give it to him yet."
Two months ago, McIlroy carried a four-shot lead into the final round of the Masters but imploded. He insisted he used Augusta as a learning experience and after two dominating days at Congressional, it seems he learned a lot.
At one point, he went 17 holes without missing a green. He went the first 35 holes without making a bogey.
After back-to-back birdies on 16 and 17, he reached 13-under par - the first time that number has ever been posted at any point in the 111-year history of the U.S. Open.
"The only one I knew about was 12-under par, when Tiger did it in 2000," McIlroy said when told about all his records - a reference to reaching, then surpassing, a number that Woods attained in 2000 at Pebble Beach.
He has now logged four rounds of 66 or less in the last year's worth of majors and been atop the leaderboard six times in the last 14 rounds.
The only thing that might stop him Saturday is time. Because second-round play was halted late Friday, 21 players had to return Saturday morning to finish. That pushed all the third-round starting times back by more than an hour. McIlroy wasn't scheduled to tee off until 3:50 p.m. EDT, giving everyone more time to watch the highlights from Friday.
His best shot in the second round was the approach on No. 8 that landed on the back of the green, bounced twice, spun backward and rolled into the cup for an eagle.
"We figured it was probably him just the way he was going," said Steve Stricker, who heard the roar from the ninth tee box.
It put McIlroy at 10 under after only 26 holes, breaking Gil Morgan's mark of 39 holes to reach double digits back in 1992. Before Friday, Morgan and Woods were the only players to reach 12 under at the Open.
McIlroy got there on the par-5 16th with a 4-iron from 223 yards that gave him a look at eagle from 8 feet. He settled for birdie, but broke the record on the next hole with a 7-iron from 175 yards that set up his 11th birdie of the tournament.
Along for the round was Phil Mickelson, a four-time major champion who rarely gets upstaged. He shot 69 to finish at 1-over 143 - normally a score that would be in contention at a U.S. Open. But probably not this time.
"He's striking it flawlessly and putted great on the greens," Mickelson said.
"His first two rounds were very impressive."
Long after McIlroy's show was over, the top three players in the world - Luke Donald, Lee Westwood and Martin Kaymer - took to the course to start playing out the string. Westwood had the best round of the three, shooting 69 to move to 1 over for the tournament. He conceded he'll almost certainly leave Congressional still in search of his first major.
Did he have any advice for McIlroy?
"I'm supposed to beat him over the next two days," Westwood said. "I'm hardly going to give him advice, am I?"
Like Westwood, Yang also hadn't reached the first tee box by the time McIlroy had finished. He wobbled between eight and six shots behind over 5 1/2 hours, including a 42-minute rain delay that thinned out whatever gallery was left to watch the race for second place.
Yang is best known as the man who took down Tiger at the PGA Championship in 2009 - the first time Woods had taken a 54-hole lead into the final round and lost. So, it figures, if anyone is going to believe anything is possible, Yang would be the man.
Or maybe not.
"I just saw that it was, like, maybe seven to nine strokes ahead for Rory, maybe even 10," Yang said, "so I didn't really think about what Rory's game was or how I'm going to catch him."