Second-round leader Jeff Quinney stumbled to a 1-over 73. He shares third place with Erik Compton (71) at 14-under-par 202. Ron Harvey Jr. (75) and Adam Speirs (69) are three strokes further back at minus-11. Rob Oppenheim is at 10-under-par 206 after a third-round 70.
Mallinger flew up the leaderboard on the front nine at Brookside Country Club. He poured in three birdies in a four-hole stretch from the fourth to get to 16 under.
The 25-year-old stumbled to a bogey on the par-3 eighth to halt his birdie run. Mallinger parred five straight holes before carding a birdie on the par-3 14th. He finished with four pars in a row from there.
Hansen bogeyed the second at the start of his round to slip to 13 under. He atoned for that mistake with a birdie on the sixth. He parred five consecutive holes around the turn.
The California native birdied the par-3 12th to get to 15 under. Hansen then birdied 15 to forge a tie for the lead at minus-16. After a bogey on the 17th, Hansen closed with a birdie on 18 to grab a share of the lead.
Eugene Smith posted a 1-under 71 Saturday and stands at 9-under-par 207. He was joined there by Scott Gibson, who shot 74 in round three.
Darren Griff, Rob Johnson, Stuart Anderson, Ricky Barnes, Brad Fritsch and Dong Yi are one stroke further back at minus-8.