Ernie Els, who held a share of the opening-round lead with Curtis, carded a 2-under 70 to join Fred Couples and K.J. Choi in a tie for fourth at 6-under-par 138. Todd Hamilton followed at 5-under-par 139, while lurking one shot further back was none other than three-time Memorial winner Tiger Woods.
'It's nice to hit the ball in the fairway, but you've got to be so patient,' said Woods, who drove considerably better Friday at Muirfield Village. 'A lot of times I took less club off the tees just to make sure I got it in play and kept the ball below the trees.'
Woods got things going early with a birdie at the second and hit his approach to 9 feet for a birdie at the par-4 third to make it two in a row. The top player in the game then played his second shot to 12 feet and made the birdie putt before reaching the green in two at the par-5 seventh.
The 28-year-old missed his eagle try, but converted for birdie to reach 4 under on the front side. Woods added a birdie at the par-5 11th but got caught up in the wind at the par-3 12th en route to a double bogey.
Woods responded with a two-putt birdie at the par-5 15th to remain well in contention heading into the weekend after a round of 68.
'I feel like things are starting to shape up,' said Woods. 'I haven't had any setbacks, things have been very positive, and I've got to keep doing what I've been doing. I feel very confident and the things I'm working on are starting to come together.'
Rose, who has been gaining experience on the PGA Tour in 2004, including at the Masters where he held the 36-hole lead, had a fiery start to his second round with five birdies over his first nine holes.
'It was just a perfect round out there, teeing off first, fresh greens, relatively no wind,' said Rose. 'It was ideal scoring conditions.'
The young Englishman birdied the par-4 14th and chipped his third shot within a few feet of the cup at the par-5 15th.
Rose converted the putt to open a significant lead before stepping onto the par-4 18th. Rose battled through the sand on his way to a double bogey to fall back into an eventual tie for first.
'I played solid, hit the ball really well, felt good,' said Rose. 'It was just a case, again, of feeling like I didn't take many chances on the greens.'
Curtis, an Ohio native who has played well so far this week in front of some home state galleries, hit a 9-iron inside a foot of the hole for a tap-in birdie at the par-4 ninth.
The 27-year-old then birdied the 15th and capped off his round with a birdie at the 18th to complete the first two days without a bogey.
'I just love this golf course. That has a lot to do with it,' said Curtis, who shot a 69. 'You've got wide fairways so I feel like I can be aggressive off the tee, and there's some key shots out there.'
Ames, who has finished in the top-7 in each of his last four events, collected four birdies over his first 11 holes to grab a share of the lead at 7 under. The 40-year-old faltered with a bogey at the 16th, but countered with a birdie at the closing hole for his share of first after a round of 68.
'There are certain flags you could have gone at and certain ones you couldn't because the greens were getting a lot firmer,' said Ames. 'That's the way Jack likes it. He's built a good golf course here. It makes you think as you go around the day.'
Scott McCarron used a remarkable eagle at the par-4 18th to complete a round of 69 and join John Daly and Kevin Sutherland in a tie for ninth at 3-under-par 141.
Tournament host Jack Nicklaus will be around to play the weekend. Nicklaus, who has hinted that he will likely leave the game in the near future, posted a second-round 73 to finish in a group at 3-over-par 147.
Nicklaus delighted the crowds at the par-3 12th after his tee shot landed squarely in the hole before bouncing into the air and landing on the edge of the fringe.
'The most exciting shot of the day was probably 12 when my ball carried into the hole, went down into the hole -- it must have bounced 20 feet up in the air,' said Nicklaus, who last made the cut at this event in 2002. 'I end up missing the green after holing it in the hole. I said, 'How long did it stay in the hole?''
The 36-hole cut fell at 4-over-par 148. Among those who failed to make the grade were Charles Howell III, Justin Leonard and Jonathan Kaye.