Three players - Kelly Chinn (Duke), Jiri Zuska (Louisville) and Julian Perico (Arkansas) - are one back at 5-under while a total of 15 golfers are within four strokes of the lead at the 36-hole mark of the inaugural Elite Amateur Series event.
After carding a 6-under 64 on Wednesday, Lewis erased three bogeys with three birdies to sign for an even-par 70 at the Sunnehanna Country Club. Meanwhile, Sekne, who opened with a 1-under 69, had five birdies and an eagle on his card en route to a second-round 65 to move into a tie for first.
Sekne, who recently concluded his freshman season at Purdue, followed his eagle on 11 with birdies on 13 and 14 and after giving a stroke back on the par-5 15th, bounced right back with a birdie on 16 on his way to an inward nine of 31.
"I felt like I got off to a decent start on the front nine but couldn't really get anything going," said Sekne, a native of Oslo, Norway. "I knew the front nine was harder and when I made that putt on 11 (for eagle), it helped he get going and from there on out things felt pretty easy."
Sekne followed his eagle on 11 with birdies on 13 and 14 and after giving a stroke back on the par-5 15th, he bounced right back with a birdie on 16 on his way to an inward nine of 31.
The day's low round belonged to Nicholas Arcement, who shot a 6-under 64. The LSU junior went out in 1-over 36 but collected five birdies and eagle for a 28 on his second nine.
The third round of the Sunnehanna Amateur will get underway at 8:00 a.m. ET on Friday with final round action slated for Saturday.