South Africa coach Russell Domingo, who is in England for the ongoing T20 and Test series, is all set to fly back home after his mother was critically injured in a vehicle accident.
But then Bairstow went for 47 and, crucially, Roy was adjudged to have obstructed the field as he attempted to return to his crease after a mix-up with Liam Livingstone.
England required 12 from the final over but Phehlukwayo, bowling yorker length outside the off stump, restricted the hosts to singles off the first three balls and debutant Liam Livingstone was run out after confusion over a second run.
England, who awarded debuts to Liam Livingstone and Tom Curran but opted against handing Craig Overton a senior bow on his home ground, won the toss and chose to field in front of a sell-out 12,500 crowd making the most of the national side's first appearance in Taunton since 1983. They two sides will play the third and final T20 in Cardiff before heading to the four-match Test series against England, beginning at Lord's on July 6.
England dropped three catches before Curran stole the show with two more wickets in the penultimate over of the innings.
England got off to the flawless start thanks to Curran, who had an instant impact after coming on in the fourth over to bowl Reeza Hendricks with his second ball in worldwide cricket to leave South Africa on 25 for one.
"You'll see everybody play at least one game - this is an opportunity to give people a chance and see what they can do on the global stage".
"We didn't deserve to win because we didn't capitalise on the start we had".
Eoin Morgan's men were asked to chase down South Africa's 174 for eight after Surrey seamer Tom Curran had become the fifth England player to take three wickets on his global T20 debut.
"We didn't play that bad (as the score suggests)", De Villiers said at the toss.
It means that the series is right in the balance going into the final game with all to play for which is exciting for both teams and their sets of fans.
"But I don't think anything can prepare you for when you actually get out there - the nerves, the adrenaline".
But fellow opener Jon-Jon Smuts made a brisk 45 with star batsman de Villiers, as he so often does, upping the tempo further with three sixes in his 20-ball innings. I asked the boys to take it one ball at a time.
Curran admits he is still a work in progress, and said: "Coming out of school I've enjoyed my first couple of summers with Surrey and I'm learning all the time with so many fine coaches and bowlers around me". "Eight overs, to go for 40 runs, you can't complain at all but at the same time we cant get ahead of ourselves".