Eger stands at 12-under-par 132, alongside Morris Hatalsky (66) and Craig Stadler (65).
John Harris and James Mason each posted their second straight rounds of 5-under 67 to share fourth place at 10-under-par 134. They were joined there by Brad Bryant (68), who shared the first-round leader with Hatalsky, Tom Kite and Jim Thorpe.
Eger opened with a two-putt birdie on the first, then dropped in consecutive birdies from the seventh to get to minus-7, before he parred his next two holes before catching fire.
The 2003 MasterCard Classic winner birdied the 11th from 3 feet out and made it two straight as his birdie putt on the par-4 12th found the bottom of the cup.
Eger kept rolling with a birdie on the 13th. He capped a run of four straight birdies at 14. However, Eger stumbled to a bogey on the par-5 15th at the Jack Nicklaus-designed TPC at Snoqualmie Ridge.
The 53-year-old bounced right back, though, with a birdie on 16. Eger gave that stroke back as he bogeyed 17 after finding a hazard off the tee, but he closed with an eagle on the par-5 18th to share the second-round lead.
'My 9-iron and putt for bogey on 17 were every bit as good as the shot on 18,' said Eger. 'I was disappointed with the bogey on 17, but I was pleased to come out with bogey.'
Stadler flew out of the gate with three straight birdies from the first to move to minus-8. After four straight pars, the eight-time winner on the Champions Tour birdied his next two holes.
The 52-year-old tripped to his lone bogey on the 10th, but Stadler parred the next three holes, then got back to minus-10 with a birdie on the 14th.
Stadler made it two in row as he birdied the par-5 15th. He closed with a birdie at the last to end at minus-12.
Like his co-leaders, Hatalsky opened with a birdie on No. 1. However, he missed the green at the third and was unable to get up-and-down for his par, but he got that stroke back with a birdie on the fifth.
Hatalsky got to 8 under with a birdie at the seventh. The 53-year-old ran off six straight pars around the turn. He ran in a 12-footer for birdie on 14 and made it two straight as his pitched his third to 5 feet at the par-5 15th.
The two-time winner on the Champions Tour made a 12-footer for birdie on 16, then made it four straight as he kicked in a short birdie putt on 17. Hatalsky missed a birdie try from inside 6 feet at the last.
'I started slow, but finished strong. I struggled with some things early and my putter was a little cold on the front nine,' Hatalsky said. 'I got things going on 14 and made four straight birdies. I just threw up on that putt on the 18th.'
Don Pooley matched the 64 of Eger in round two. Pooley climbed into a share of seventh place at 9-under-par 135 and he was tied there by Thorpe, D.A. Weibring and Kite. Hale Irwin and Bruce Lietzke are one stroke further back at minus-8.