Hank Kuehne is alone in second place after firing an eight-under 64 Saturday. He stands at 14-under par, three shots ahead of Iain Steel, who is in third at minus-11.
Thunderstorms halted play twice Saturday totaling almost three hours of down time. After the first suspension of play, the horn sounded only 19 minutes later bringing everyone back inside. The second suspension lasted almost two hours.
'It wasn't too bad because we hadn't started and it was almost like having a later tee time,' said Grob of the suspensions. 'I was just happy we finished the round. I didn't want to have to come back for the last couple of holes tomorrow morning.'
Grob shared the 36-hole lead with Derek Gillespie and quickly broke out of the pack. Grob collected two birdies on the front side and eagled the par-five fifth for the second time in as many days.
Grob continued his fine play with birdies at 11, 14, 16 and 17 but stumbled with a bogey at the par-five closing hole. Despite the bogey at 18, Grob will carry a one-stroke lead into the final round.
Kuehne, the 1998 U.S. Amateur champion, was flawless Saturday. He tallied six birdies along the way and closed the gap to one when he chipped in for eagle at the 18th at the Mark O'Meara Course at Grandview.
'That was a nice way to end, but I thought I had a lot of solid putts all day that just wouldn't drop,' said Kuehne. 'I saw a line and hit it right there, but sometimes you have to get a little lucky. I am looking forward to playing some good golf with Mike Sunday, and we'll see where we are at the end of the day.'
Gillespie struggled to an even-par 72 in the third round and is alone in fourth at eight-under par. David Hearn, Jeff Quinney and Jim Rutledge share fifth place at minus-seven.