Woods entered the week 25th in the FedEx Cup points standings, meaning he needed to put forward a solid week to remain in the top 30 and qualify for the Tour Championship for the first time since 2013.
Northern Ireland's McIlroy briefly threatened to dislodge Woods before equalling the American's score.
"Just the way it goes", Woods said with a smile, caring more about a complete round of golf and a strong performance with his old putter than whether he was leading after one round in the FedEx Cup playoffs.
McIlroy had been a shot clear of Woods at nine-under par after 15 holes when Woods headed for the clubhouse.
The man in the box seat for the last ticket to Paris remains the equally impressive Tony Finau, who matched his rival's 64 on Friday to lie five off the lead and continue his wonderful form this season, including three top 10s in the four majors and two top-four finishes heading into this event.
The two-time FedEx Cup victor added two more birdies to his card on the back nine, but a costly lip-out bogey on No. 17 and a three-putt on the 18th pushed him back to even par for the day. He came to the 18th hole looking up at Woods on the leaderboard, but vaulted into first place by reeling off six consecutive birdies to get to 9-under for the tournament.
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The birdies started flowing on the first hole and kept rolling throughout the day.
"I've got to make birdies", Woods said.
Woods managed an eagle and seven birdies and his only hiccup being a late bogey on his back nine at the Aronimink Golf Course in Philadelphia. But he quickly ran off birdies at 13, sticking his approach inside 5 feet, and 16 to get back under par for the day.
Jordan Spieth, the third member of the star-studded group, was even through 11 holes.
Woods was posing on his tee shot at the par-3 fifth, the sun glaring into him, and he couldn't figure out immediately where it went.
"The heat is hard for me because I lose so much weight out here", said Woods.
Kei Nishikori is headed to the US Open semifinal following a dramatic upset victory over Marin Cilic on Wednesday. Keys said she will look to home support on Thursday when she resumes her rivalry with Osaka.
Del Potro - the 2009 victor of the men's singles at Flushing Meadows - breezed past Borna Coric in the final match of the day. Serena, seeded 17th, routed Venus 6-1, 6-2 in matching the most-lopsided victory in the Williams sisters' series.
Maximum sustained winds of the unnamed system have been clocked at 30mph and the system is moving west-northwest at 15mph. If Gordon were to take more of a turn to the north then our forecast could change considerably by Wednesday and Thursday.
Government spokesman Yoshihide Suga said two people had been killed, with local media reported around 40 were missing. Houses in the town were hit by landslides, and one report said five residents were found with no vital signs.
Michael Capuano (D-MA) conceded to Boston City Councilwoman Ayanna Pressley after polls closed in the state. Pressley defeated Capuano by arguing that it was time for a change in representation in the district.
The report added that five cars and a mini bus are trapped underneath piles of debris from the collpaed section of the bridge . My thoughts are with the families of the victims. "I pray that those who are injured recover at the earliest".
For instance, the electricity went out in an annex on the site, causing some frozen specimens to begin to rot. In 2015, for example, a blaze destroyed the prestigious Museum of the Portuguese Language in Sao Paulo .
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Wisely, Unsworth himself has elected to let Wood do all the talking for him-and to let Musk keep packing the evidence folder. Mr Unsworth's lawyer Mark Kennedy from the firm Howard Kennedy told the BBC that Mr Musk's allegations were baseless.
Storm Gordon weakens after landfall in southern US
A child has been killed in Florida after a tree was blown on top of his mobile home in an incident which may be linked to Gordon. Brandon Drake, a meteorologist for the National Weather Service in Topeka, said theories differ on how the storm will progress.
Dallas Cowboys: Earl Thomas trade still on the table
Thomas' reaction to the lack of a resolution was clear in his post: "The disrespect has been noted and will not be forgotten". Thomas has since reported to the Seahawks, but he still doesn't appear to be thrilled with his situation.