Former U.S. Open champion Scott Simpson fired a course-record, 11-under 61 to move into a share of second place at 11-under-par 133. He was joined there by first-round leader Massy Kuramoto (70).
Tom Kite carded a 64 to move into a tie for fourth place at minus-9. He stands alongside Graham Marsh (69) and Des Smyth (66).
Pooley was hot early as he birdied three of the first four holes on the TPC at Snoqualmie Ridge to move to minus-8. He gave a stroke back with a bogey on the sixth.
The 54-year-old, who won the 2002 U.S. Senior Open, atoned for that mistake with a birdie on the par-four seventh. Pooley rolled in an 8-footer for birdie at eight to move to minus-9.
Pooley, who owns two Champions Tour wins, grabbed a piece of the lead with a birdie on the 11th. He got up and down for birdie on the par-5 15th to get to 11-under. He drained a long birdie effort on the 17th to end at minus-12.
'That wasn't even makeable and that went in,' joked Pooley of his long birdie putt on 17. 'I got a new putter this week and its working pretty darn good. I hit the ball very well today and made a whole bunch of putts. That was a very good putting day.'
Simpson started on the back nine Saturday and flew out of the gate with three straight birdies from the 10th. He then carded back-to-back birdies from the 14th to get to 5 under through six holes.
The 50-year-old birdied three straight from the 17th as he played his first 10 holes in minus-8. With a 59 in his sights, Simpson birdied the third, but parred his next two.
Simpson got to minus-10 with a 10-foot birdie putt on the par-3 sixth. He still had a chance to shoot 59, but his 8-foot eagle putt on the eighth slid by the hole.
He tapped in for birdie and then needed an ace on the par-3 ninth to post 59. Simpson, however, pulled his tee shot well left of the green. He pitched inside two feet and tapped in for par.
'It was fun, a lot of fun,' Simpson stated. 'That was the best round I ever shot. It didn't seem that hard, because I just kept hitting a lot of good shots. I putted much better today too. I haven't putted well recently.
'I knew with three holes to go that I had a shot for 59. That was pretty cool. I've never been there before. I just missed putts on 16 and 17. I knew I had a shot if I made that putt on 17.'
Kuramoto was up and down all day. He birdied the first, but struggled to three straight bogeys from the fifth to slide to minus-7. He birdied eight and nine to get back to even-par for his round and 9-under overall.
The 50-year-old from Japan wrapped bogeys on 10 and 12 around a birdie on the 11th. Kuramoto birdied 13 and made it two in row as he also converted a birdie on 14. He drained a 6-footer for birdie at the last to end in a share of second.
Mark Johnson fired a 7-under 65 to move into a share of seventh at 8-under-par 136. Johnson was joined there by David Edwards (71), Walter Hall (68), Wayne Levi (68) and Doug Tewell (69). Keith Fergus, Mike McCullough and Mike San Filippo are one stroke further back at minus-7.
The Golf Channel will televise all three rounds beginning Friday at 4:30 p.m. ET.