Glamorgan 323 for 7 (Root 113*, de Lange 58*) beat Surrey 259 (Clark 79, Meaker 50, de Lange 4-63) by 64 runs
An unbroken century stand between Billy Root and Marchant de Lange allowed Glamorgan to fight back from an indifferent start to claim their first victory of the Royal London Cup season, leaving Surrey stranded on just one win.
Root was unbeaten on 113 and de Lange 58 not out as Glamorgan recovered from 160 for 6 to post a total of 323 for 7, thanks largely to the unbroken eighth-wicket stand between Root and de Lange, who put on 113 off 63 balls. The home side then bowled Surrey out with 20 balls to spare - de Lange chiming in with four wickets and Graham Wagg taking three - to win by 64 runs.
De Lange accounted for the Surrey top order with a devastating spell of 3 for 14 from his opening three overs, as the visitors slumped to 28 for 4 in the fifth. Will Jacks was bowled off his pads and Rory Burns was well caught low down at third man, before Dean Elgar slapped one to cover. Earlier, Mark Stoneman was undone by Michael Hogan, with David Lloyd taking a low catch at first slip
Jamie Smith, a promising 18-year-old batsman, and Ben Foakes staged a recovery by adding 64 for the fifth wicket, before they were dismissed in quick succession. Smith was well held by Chris Cooke, standing up to Graham Wagg, who then had Foakes caught at mid-on.
Jordan Clark, who joined Surrey from Lancashire this season, top scored for his new county with an aggressive 79, and his partnership of 107 with Stuart Meaker gave Surrey a glimmer of hope. There were 108 needed from the final 10 overs, but de Lange captured his fourth wicket when Clark, who had struck the previous ball for six, holed out at long leg.
Meaker (50) achieved his career best List A score, but with 70 needed from the last five overs, there was little hope for the visitors, with de Lange ending with 4 for 63.
The home team, who had been put in on a pacey pitch, were soon in trouble against Morne Morkel, who dismissed the first three batsmen with a superb display of seam bowling.
Marnus Labuschagne was the first to go, plumb in front of a full-length ball, before Cooke was bowled by one that trimmed his off stump, then Jeremy Lawlor guided one the gully.
Lloyd struck Conor McKerr for three successive boundaries but, attempting to pull a short delivery from Meaker, he holed out at mid-wicket.
Charlie Hemphrey and Wagg helped Root take Glamorgan past 200, before de Lange began his assault. He began with successive boundaries, before a flurry of enormous sixes gave Glamorgan hope of a substantial total.
Root reached his century - his second in List A games - from 111 balls and, from the next ball, de Lange reached his first fifty for Glamorgan from just 27 balls. They both achieved career best scores, as 113 runs were plundered from the final 10 overs and 51 from the final five.
Root said: "It was great to get not only my career best, but also to win the game. Marchant played a terrific innings and it made my job a lot easier."
De Lange added: "I played my own game. I am not a top order batsman and if the ball is there to be hit I'll have a go. My job was to support Billy, and it worked."