"I hit a beautiful 7-wood there, like 3½ meters or less," Jimenez said about the eagle. "All day long been hitting quite well and I played decent really. ... I think I played very well all day. Four-under par with these conditions, I think I played very well."
Cejka shot a 67 in the round delayed 90 minutes late in the afternoon because of rain to match Jimenez at 9-under 135 at Prestonwood Country Club.
Bernhard Langer (66) was a stroke back with Scott Dunlap (68) and first-round leader Scott Parel (71). The 64-year-old Langer, the tournament winner in 2012 and 2018, leads the Charles Schwab Cup points race.
"Played pretty decent all along," Langer said. "Yesterday, I played brilliant and didn't make anything. Today, I played almost as good and made a few putts and that was the difference."
The 57-year-old Jimenez, from Spain, has 10 victories on the 50-and-over tour.
"I'll do my best," Jimenez said. "I'm hitting good, I'll see on Sunday. The guys out there -- Cejka's playing really good, too, Langer's playing well. Strong field."
Cejka won the major Regions Tradition and Senior PGA Championship in May for his first senior titles. The 50-year-old Czech-born German won his lone PGA Tour title in Puerto Rico in 2015.
"I played pretty good," Cejka said. "It was tough out there. It was a little bit windy, but I hit a lot of good shots. ... Could have been one or two more better, but I take it where I am right now concerning what we had the last three holes with the rain delay. So I'm just happy where I am right now. I'm excited for tomorrow."
The top 72 players on the money list after the regular-season finale will advance to the playoffs. A wild-card playoff spot also is available for a player outside the top 72 who finishes in the top 10 this week.
Defending champion Ernie Els was even par after a 73.