Aiken shot a nine under par 63 with 10 birdies and just one bogey, while Walters recorded a 64 as both players moved 17 under to hold a two-shot lead ahead of South Korea's Jin Jeong.
Jeong had five birdies, an eagle and a single dropped shot in his round of 66, with Finland's Roope Kakko a stroke back in fourth following a 67.
However, it was a mixed day for Scotland's three representatives. Two-time European winner Alastair Forsyth had headed the field after three birdies in the first five holes and goes into the final round firmly in contention - four shots behind the leaders on 13 under par.
But any thoughts of glory have vanished for Craig Lee who was leading at the halfway stage along with Edoardo Molinari but tumbled down the leaderboard to finish the day in a 12-way tie for 18th place on nine under alongside England's Ross Fisher. Lee's demise came after he scored a 74 as he doubled bogeyed the 12th hole as well as hitting three birdies and three bogeys.
And it was a day to forget for David Drysdale, who shot a round of two over par to finish the day in a four-way tie for 67th place on three under.
The event is certainly worth winning with three places in this year's Open Championship at Royal Liverpool up for grabs, along with a first prize of £170,000 and Walters admitted he was pleased to put himself in a strong position ahead of today's final round.
"I hit the ball so well," he said. "I made a strong effort to be aggressive. This is a good opportunity, and I will be nervous, but hopefully I can improve on my record in South Africa."
The 33-year-old rose to prominence last season when he finished second in Portugal courtesy of a 60-foot putt on the final hole that saw him break down in tears as he secured his European Tour card two weeks after losing his mother to cancer. And his fighting qualities were on display again as he responded to a bogey at the 16th with an eagle at the par-5 18th.
Two-time European winner Aiken performed similar heroics which included sinking a 20-foot putt at the 11th and an unlikely 50-foot effort on the 14th. The 30-year-old finished with a birdie from six feet at the 17th and got up-and-down at the par-5 last for a 10th birdie of the day.
"I've been in a lot of final groups so I know what pressures there are going to be," said Aiken. "If you just go and do what you do best, stick to your game plan and take it shot by shot then the best golfer will win."
In seventh, England's David Horsey remains in contention after scoring 70, while former Ryder Cup player Molinari sits six shots off the pace following a third-round 72, peppered with bogeys on the second and third holes, and again on the 15th and 16th to sit eighth in the standings.