Phelan had six birdies and just one bogey at East London Golf Course. Ford made five birdies and was bogey-free.
Ireland's Phelan followed up his tie for second at the Joburg Open last weekend. He started on No. 10 in blustery conditions, with his slip on his second hole his only bogey.
England's Ford joined him at the top of the leaderboard after producing the only flawless round of the day.