The 29-year-old, fresh from victory on the European Tour in last weekend's rain-shortened Nelson Mandela Championship, added a four-under-par 68 to his opening 70 for a six-under aggregate of 138.
Jamieson is seven shots behind the joint leaders, Charl Schwartzel and Gregory Bourdy, who burst away from the field to be four clear at the top. Bourdy posted a 65 while Schwartzel, the former Masters champion, had a blemish-free 64, with six birdies and an eagle.
The South African won the Thailand Championship last Sunday by 11 shots with a 25-under score and he already is 13-under this weekend over a course where his record includes one win and four second places.
"The course was there for the taking and, luckily enough, I took advantage early on," said Schwartzel after joining first-round leader Bourdy at the front on 131.
David Drysdale posted a 72 to finish in a share of 30th on 141 while George Murray, runner-up in this event last season, moved up with a 69 for 142. Peter Whiteford and Marc Warren both made the cut on 143 and 144 respectively but Callum Macaulay, Craig Lee, Scott Henry and Alan McLean were among the early casualties.
n Pamela Feggans and Vikki Laing are the leading Scots on two-under 142 in the Ladies European Tour Final Qualifying School at Marrakech, Morocco, after Heather MacRae followed her opening 68 with a 76.
Feggans, from Patna, Ayrshire, shot two-under 70 for 142, while Laing, from Musselburgh, followed up a 69 with a 73. They are joint 43rd and the top 60 and ties after four rounds advance to Monday's final 18 holes at the Al Maaden course. MacRae is joint 59th.