Half of the field was forced to return to the Laurel Valley Course Saturday to complete their second rounds due to rain and fog delays over the first two days.
Allenby stands at 9-under 135. Rocco Mediate, who is a course member, shot 68 Friday to take the overnight lead at 7-under, but was passed by the surging Australian in the morning.
Allenby made seven birdies inside of eight feet and felt he should have been able to pull farther from the field.
I dont recall hitting a bad shot, said Allenby, who won this years Nissan Open in a six-man playoff.
If I could have holed some more puttsI had six putts inside 10 feet. I had that on nearly every hole.
Flesch, who was tied with Mediate at 7-under when play was suspended Friday, twice made his way to 9-under, but a double bogey on No. 17 took him out of the lead. He finished with a birdie at the home hole to shoot 67 and get within one of the lead.
The final group is scheduled to start their third rounds at 3:09 p.m. ET.
Full-field scores from the Marconi Pennsylvania Classic