Waring, who is seeking his first European Tour victory, birdied five of the last 10 holes and finished the day at 16-under 197 over three rounds.
Jamieson carded an 11-under 60 Saturday to storm into second place, two shots behind Waring.
Second-round co-leader Hennie Otto (69) was tied with Jamieson in second place, along with Simon Thornton (65) and James Donaldson (66).
Jamieson was on the road to a 59 in his third round but missed a birdie on the final hole at the Oceanico Victoria Golf Club. Jamieson had 11 birdies and no bogeys Saturday after a 73 Friday.
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