Lunde, who claimed his first Nationwide Tour victory in July, birdied every third hole in a flawless round at Hillcrest Country Club ' a fact he didn't realize until he got to the interview room.
'It worked out pretty well,' said Lunde, who was at 11-under-par 131 for a two-shot lead.
Spencer Levin and Tag Ridings both shot a 5-under 66 to move into a share of second place at 9-under 133. Chris Tidland had a 65 to lead a group of six players who were knotted at 8-under 134.
Overall, there were 20 players within five strokes of Lunde heading to the weekend.
Lunde, who earned his first win at the Nationwide Children's Hospital Invitational two months ago, picked up enough birdies Friday to take the lead despite hitting only six of 14 fairways.
'Don't tell everyone that,' he joked. 'Can't we let them think I played really good today?'
Despite that dearth of accuracy, Lunde made it around the par-71 layout without dropping a shot. He has made only one bogey through the first 36 holes.
'I missed quite a few fairways by just a little, but I got away with getting some pretty decent lies, so that was key,' Lunde said of his second round.
'I really only struggled on one hole,' he said, and that hole turned out to be the par-5 16th, where Lunde pulled his tee shot into the trees and was forced to kick his second through the fairway and into the rough.
In the end, Lunde holed a putt over 50 feet to save a par ' and his bogey- free round.
'That's probably the ugliest par I've made in a while. It all goes down the same (on the scoreboard),' he said. 'It's putts like that that keep the momentum of a round and a tournament going.'
The cut line fell at 3-under 139 with 65 players moving on to the weekend.