Surrey opened their Clydesdale Bank 40 account with a 105-run victory over Somerset in a replay of last season's final at the Kia Oval.
Led by Rory Hamilton-Brown, who set the tone with 101 off 89 balls, the defending champions posted a daunting 295 for six before Stuart Meaker, Zafar Ansari and Gareth Batty, who took three wickets piece, combined to dismiss Somerset for 190.
With Vernon Philander resting a sore back, Alfonso Thomas on Indian Premier League duty and Steve Kirby ruled out with a thigh injury, Somerset's attack contained four bowlers aged 20 or under, including 18-year old debutant Jamie Overton.
Having been put into bat, the Lions openers took full advantage, laying the foundation for a sizeable total by racking up 163 in 23 overs.
Hamilton-Brown was dropped at short mid-wicket on 13 and Steven Davies survived a caught and bowled chance, on 39, off Craig Meschede.
In the 15th over, Hamilton-Brown launched George Dockrell over long-on for six. In the next, the Surrey captain simultaneously brought up his fifty, off 53 balls, and the hundred stand.
Davies posted a 45-ball half-century and Hamilton-Brown clubbed a second maximum off Dockrell. But the re-introduction of Peter Trego produced the wicket of Davies, who was bowled around his legs for 72.
Hamilton-Brown moved to his second hundred in one-day cricket, which came from 87 deliveries, only to fall, moments later, to a catch on the straight boundary.
Jason Roy was lbw attempting to reverse sweep Max Waller to make it 193 for three. But then Tom Maynard and Zander de Bruyn flayed 63 in just eight overs.
Maynard, who was dropped on one, was eventually caught at mid-on off Lewis Gregory for 28.
De Bruyn, who made 34, was undone by Meschede's reverse swing and Ansari fell to a superb catch by Craig Kieswetter, leaving Spriegel and Batty to add icing to the cake.
In reply, Somerset suffered the early setback of losing Kieswetter, beaten for pace by Meaker, and Trego, who was caught and bowled by Jon Lewis.
Nick Compton and James Hildreth combined for 48 in six overs before Hildreth danced down the wicket to Batty's second ball to go stumped for 21.
Compton moved to a 48-ball fifty in the 18th over before drilling the ball back to Ansari in the next.
With the 20-year-old slow left-armer striking again, when Arul Suppiah chopped on, and Jos Buttler, attempting a reverse sweep, going caught behind off Batty for 29, the writing was on the wall.
Meschede, seeking to lift Batty over long-off for a second successive six, went for 20. Waller was bowled around his legs by Ansari and Gregory, driving, was caught behind off Meaker, who applied the coup de grace by yorking Dockrell.
