Winless since his 1998 U.S. Open triumph, Janzen is trying to regain the mental edge that has produced two majors and the 1994 Players Championship.
Entering the final 36 holes, Janzen leads Joe Durant (69) by one shot at 9-under-par. Tom Pernice, Jr., is two back after a round of 67. Kevin Sutherland (69) and Hal Sutton (68) are tied for fourth, three off the lead.
For the second straight day, Janzen overcame a pair of bogeys to climb to the top of the leaderboard.
This time, Janzen bogeyed the 8th and 9th holes, only to birdie the 15th, 16th and 17th holes for a back-nine 32.
Thats the key. Instead of being timid and less aggressive after making bogey, you have to stay with it and comeback with birdies, said Janzen, who tied for fourth here last year.
After getting up and down from the greenside bunker on the par-5 15th for birdie, Janzen rolled in a pair of 20-footers on the 16th and 17th holes to complete a flawless back nine.
Janzen, the 1993 and 98 U.S. Open champion, is in search of his ninth career Tour triumph, and his first in nearly three full seasons.
This year, the 36-year-old has earned only one top-10 in ten starts. Weekend scoring has proved to be a problem.
After opening with a pair of 67s in the Genuity Championship, he carded a third-round 77 to fall from contention.
At the Honda Classic, Janzen shot a final-round 75. Then, in the Masters Tournament, he ballooned to a 79 on Sunday.
Still, Janzens 36-hole total this week has him confident entering the final two rounds at the TPC at The Woodlands.
Its a matter of believing I can win, he said. I havent won because I havent believed I could win. If I can go out this weekend like I have the first two rounds, I think I can win.
Durant has already won twice this year. He captured the Bob Hope Chrysler Classic, setting a 90-hole tour scoring record in the process. He then captured the Genuity Championship in his next start.
Friday, Durant successfully navigated the shifting Texas winds to the tune of four birdies and one bogey.
Durant played alongside Chris DiMarco and John Daly. DiMarco birdied three of his first six holes, while Daly birdied three of his first four.
The guys got off to a great start and I just played off of that, said Durant. Im very happy with where Im at.
DiMarco wound up shooting 70 to finish at 5-under-par, four off the lead. Daly is one shot back after shooting 69.
Fred Couples, who started the day one shot off the lead, shot 4-over-par 76. The former Houston Cougar is now at even par after playing his final four holes in 5-over.
Full-field scores from the Shell Houston Open