Published: Sep 16, 2011 11:32 PM EDT
Updated: Sep 17, 2011 6:30 AM EDT

LEMONT, Illinois (AP) - England's Justin Rose made an eagle on the 15th hole to shoot a 3-under 68 and hold on to a share of the lead with Mark Wilson at the BMW Championship on Friday.

Coming off an opening round 63, his best round of the year, Rose said he felt flat at times on Friday, especially early on the back nine on a cool, overcast day in the Chicago suburbs.

But a 3-iron into 30 feet for an eagle on the par-5 15th woke him up, and not even a bogey on the last hole changed his outlook going into the weekend of the FedEx Cup playoff event.

"You never quite know what to expect after playing so well in the first round," Rose said. "Actually, my caddie said it's the best round he's seen in 20 years out there from a ball-striking perspective. So, there's only one way to go from there. But today was good."

It was even better for Wilson, who considers Cog Hill a home course after he moved to the Chicago area. He ran off four straight birdies around the turn, starting with a wedge to tap-in range at No. 8, and was steady the rest of the way for a 66.

They were at 11-under 131 overall.

Webb Simpson, who leads the FedEx Cup and has won two of his last three tournaments, made his only bogey of the tournament on the fifth hole but was otherwise solid in his round of 68 that left him two shots behind.

Australia's John Senden, who is No. 55 in the FedEx Cup standings and needs a top-five finish to advance to the Tour Championship, had a 66 and was alone in fourth place at 134. Bill Haas was another shot back after a 66.

This is a pivotal week for two cups.

The BMW Championship is the final tournament for the top 10 players for U.S. and International teams to qualify for the Presidents Cup.

Brandt Snedeker (No. 11) had a 66 and was in a share of seventh with a group that included David Toms (No. 10). Also at 5-under 137 were Australians Geoff Ogilvy and Robert Allenby, both of whom are on close to the cutoff for the International side.

For the FedEx Cup, the top 30 advance to the Tour Championship at East Lake Golf Club in Atlanta for a shot at the $10 million prize.

Wilson, a two-time winner early in the season, already is a lock for East Lake. He would have to win the BMW Championship to earn a spot on the Presidents Cup team, although it could come with an even greater bonus. No one on the PGA Tour has really stood out this year, and these next few weeks are likely to go a long way toward deciding player of the year.

For Wilson, whose tournament wins were eight months ago against fields that were not terribly strong, a win at Cog Hill could put him in contention.

"That would put me with the most wins of anybody, and then going into East Lake if I can get another one there, I think I'd have a good argument. That's a lot of 'ifs,'" Wilson said. "I've played great so far. There are a lot of great players out here, but I feel like I'm playing very close to the same form I had when I started the year out."

Rose is at No. 34 and still looking at this week as having nothing to lose - he wasn't in the top 30 when he arrived at Cog Hill, so the Englishman figures he could only give it his best shot.

"I think it's more of a mental shift," he said. "It's not putting pressure on yourself, it's not getting frustrated out there, it's having the ability to stay a little more patient, and I think that's what I'm feeling this week."

Phil Mickelson is not feeling it. He started his round by missing three birdie putts inside 8 feet - two of them from inside 4 feet - and then had four bogeys on his back nine for a 73 that put him 14 shots behind.

England's Luke Donald, the world No. 1, bounced back from an opening 75 with a 66 that at least got him to under par.