Swedish Challenge Tour graduate Sjöholm started his second round on one under, five behind overnight leaders Stephen Dodd and José Manuel Lara.
But he started both his front nine and back nine with a hattrick of gains, to be six under through 12 holes and seven under for the week.
He was joined by France's Jacquelin, who was yet to drop a shot in the tournament 11 holes into his second round.
Englishman Wall completed the leading trio - he was two under for the day through 11 - while Dodd was yet to resume after his opening 65.
Lara had dropped three shots and was back on three under with three to play, but Spaniard Ignacio Garrido reached the turn in 32 to join Dodd on six under.
|T3||LARA, José Manuel||ESP||18||-7|