Somerset won the toss and scored 132 in their allotted 20 overs in the Rajiv Gandhi International Stadium in Uppal.
The Eagles reached 133/5 in 18.4 overs.
The Bloemfontein-based franchise made relative light work of the pursuit of the target thanks to a superb half-century stand between Van Wyk (47, 41 balls, 4x4, 1x6) and Ryan Bailey (29, 24 balls, 4x4).
They featured in a partnership of 59 off 5.5 overs for the fourth wicket.
They went after the bowling of Peter Trego and Max Waller in the middle overs.
Van Wyk smashed a beautiful six over mid-wicket off the leg-spinner Waller.
Bailey and Van Wyk rotated the strike well and kept the intensity going, obviously learning from their tied encounter with Sussex in the league phase of the Champions League at Delhi.
Earlier, Rilee Rossouw slammed 12 runs off four balls from the left-arm swing bowler Charl Willoughby before he was caught at mid-on by Alfonso Thomas for an attractive 13.
Bailey and Van Wyk perished close to the end with the scores on 126 and 132, spoiling what could have looked like a much more comprehensive thrashing.
Willoughby, with 2/29 from four overs, and Thomas, with 2/20 from 3.4 overs, were the pick of the Somerset-attack.
Somerset started off in disastrous fashion by losing Gary Kieswetter (eight) and Arul Suppiah (nought) in the first over bowled by De Villiers.
The lanky fast bowler also accounted for Zander de Bruyn when he had him caught off a failed pull shot for two.
Somerset, under immense pressure on 52/5, regrouped thanks to a superb half-century from Wes Durston.
He resurrected their innings and pulled them to 132/8. Durston scored 57 off 32 balls, with ten fours and featured in a 77-run partnership for the sixth wicket with James Hildreth, who contributed 31 off 40 balls (2x4).
But De Villiers succeeded in removing Durston in the 19th over to restrict Somerset to 132, instead of a more challenging score closer to 150.
De Villiers finished with 4/17 from four overs.
His new ball-partner, Jandré Coetzee, with 2/24 off four overs, and Alan Kruger, with 1/18 from three overs, were instrumental in keeping the Somerset-score about 30 runs short of a competitive total on this dry pitch.
Teams:
Gestetner Diamond Eagles: Boeta Dippenaar (capt), Rilee Rossouw, Adrian McLaren, Dean Elgar, Reeza Hendricks, Ryan Bailey, Ryan McLaren, Morné van Wyk (wk), Dillon du Preez, CJ de Villiers, Thandi Tshabalala, Victor Mpitsang. Somerset: Justin Langer (capt), Jos Buttler, Zander de Bruyn, Wes Durston, James Hildreth, Craig Kieswetter (wk), Ben Phillips, Arul Suppiah, Omari Banks, Alfonso Thomas, Charl Willoughby, Max Waller, Mark Turner, Ben Trego.