Potchefstroom - Half-centuries from captain Andrew Strauss, Jonathan Trott and Matt Prior paved the way to a confidence boosting victory for England ahead of their one-day series against the Proteas as the tourists earned a four-wicket win over South Africa A in a warm-up match in Potchefstroom on Tuesday.Chasing 280 runs to win, England reached 281 for six with 11 balls to spare to sneak home against a full strength SA ‘A’ side.Strauss shared 68 runs with Joe Denly (23) for the first wicket and another 45 with Trott for the second. The skipper made 65 runs off 71 balls, including seven boundaries, for his 40th career fifty, and after he was caught behind off the bowling of CJ de Villiers in the 22nd over, Trott took control of the innings.The 28-year-old top order batsman looked to be heading for a century, but got carried away with the run-rate slipping away from them in the late stages of England’s run chase.With 64 still needed from the last seven overs, Trott got hold of Morne Morkel, who had bowled superbly to that stage but was smashed for successive boundaries before he got revenge, dislodging the batsman’s middle stump.Trott contributed 78 from 89 deliveries with four boundaries and a six for his 31st half-century. Prior then combined with Luke Wright, who was unbeaten on 25, in a 46-run stand for the sixth wicket.And while he was removed by CJ de Villiers in the 48th over, Prior had done enough to ensure his team of victory, contributing 54 off 48 – his 24th half-century – with seven fours and a six.De Villiers and Rory Kleinveldt were the pick of the bowlers, picking up two wickets apiece.The South African A team’s top order had earlier laid a solid foundation as they reached 279 for nine after winning the toss and opting to bat.Skipper Hashim Amla and opening partner Andrew Puttick got the South Africans off to a good start with a 77-run stand for the first wicket.Pace bowler Wright, however, earned the breakthrough in the 15th over when Amla, who made 37 off 43 balls, gifted Strauss a regulation catch at silly-mid on.Rilee Rossouw then combined with Puttick as the pair added 45 for the second-wicket before Rossouw, who contributed 28 off 26, swept spin bowler Adil Rashid to deep square leg and was run out by Wright coming back for the second.In the 27th over Strauss introduced Denly and the part-time spinner immediately made an impact when he removed Puttick with his fourth delivery.The opener tried to go big but got a top edge and handed Tim Bresnan a sitter at deep mid-wicket. Puttick made 62 off 74 balls – his 12th career half-century – including five boundaries.England did well to restrict the middle order, but Heino Kuhn, who smashed an unbeaten 42 from 46 deliveries, kept the tail wagging. Kuhn shared 40 runs for the eighth wicket with Morkel, who made 29 before he was removed by Bresnan.Wright and Graham Onions led the England attack, bagging two wickets each.England play South Africa in the first of five one-day internationals at the Wanderers on Friday.