England 212 for 6 (Morgan 73, Trott 71) beat South Africa 211 (Amla 43, Elgar 42, Anderson 4-44, Dernbach 3-44) by four wickets
Scorecard and ball-by-ball details

Eoin Morgan swore allegiance to England's Test team this week ahead of all other temptations. In the current climate he would be foolish to suggest anything else. There may be suitors from the IPL who do not entirely believe it and their appetite to find out more will only have been whetted by his dashing intervention at The Oval which took England back to the top of the ODI rankings.

England beat South Africa for the first time this summer as their four-wicket victory with two overs to spare levelled the series at 1-1 with two to play. They also reclaimed the title of the No. 1 one-day side in the world, although this accolade could be short-lived. South Africa's reign lasted three days and they may reign again by Sunday evening. Fortunately, the players keep these things in perspective. Some of the more rabid fans would be well advised to follow suit or their emotional highs and lows may prove terminal.

Morgan made 73 from 67 balls, but he had a rock to lean on: Jonathan Trott, met by a target well within his comfort zone and bent upon batting through the innings. When the game was in the balance, at 64 for 3 in the 18th over, it would have been a toss-up which batsman South Africa most wished to dismiss next. Morgan could fearlessly slash and burn but Trott was the smouldering menace.

By the time they removed either of them - Morgan offering a return catch to Robin Peterson, aiming over midwicket - England's alliance of opposites had garnered 108 in 20 overs and the match was almost spent. The only surprise was that Trott did not see it through. He was out with England five runs short, 71 from 125 balls, as Wayne Parnell had him caught at the wicket. Parnell completed a niggardly spell but for Dale Steyn, back in the side, the pitch offered little encouragement.

England's chase had never looked entirely comfortable against a persistent attack and on a low, holding surface. But Trott created order out of discomfort; approaching his task like a librarian, ticking off every ball and stacking it neatly in alphabetical order. South Africa, probably 30 runs shy, could do little about it. "We were hoping for 250-odd," said AB de Villiers, South Africa's captain. "Most of the senior players got in and got out. That was the big sin."

Ravi Bopara was not so composed. He left to the sound of booing from the crowd, adjudged by umpire Kumar Dharmasena to be caught at the wicket for nought off Morne Morkel. He immediately turned to the DRS and the crowd only witnessed the fact that Hot Spot showed no edge. But the sound as the ball passed the bat was clearly audible - convincingly so - and the third umpire, Simon Taufel, correctly concluded that he had no clear evidence to overturn the on-field umpire's decision.

Bopara had bowled his bothersome medium pace skilfully in South Africa's innings, conceding only 31 runs and claiming the wicket of Faf du Plessis in only his second completed bowling stint for England, following a full shift against Bangladesh at Edgbaston two years ago.

It has been a fraught period for Bopara, his cricketing summer affected by domestic issues, and this will have helped to persuade him that much of his England career, especially at one-day level, remains ahead of him, but his pressing need in the last two matches is runs.

Until Morgan shook the duvet, the cautious nature of England's reply was summed up in the dismissal of Alastair Cook, who reached 20 from 47 balls when he pulled Peterson gently to deep midwicket, an nondescript delivery but a wicket achieved through a gradual build up of pressure.

South Africa had to put in a workmanlike performance to post anything like a competitive total. Jade Dernbach held them back. His opportunities for England in limited-overs cricket this summer have extended no further than south London, but the moment he dismissed Hashim Amla, England's scourge all season, ensured him of an influential day. South Africa's last eight wickets slipped away for 91. England were sharper than they had been at the Ageas Bowl.

Fresh from his 150 in the second ODI in Southampton, Amla made unflustered progress to 43 from 51 balls before Dernbach took advantage of limited footwork in his first over to bowl him between bat and pad. Until then, he had batted with tranquillity and purpose, his runs advance unnoticed like a night-time tide. One whip behind square against James Anderson was so wristy that you could swear he played it with the back of the bat.

Dernbach, whose only other one-day appearance came against Australia , also on his home ground, was given an opportunity after England left out Tim Bresnan and overlooked the man who might have been viewed as his most like-for-like replacement, Chris Woakes. Dernbach has twice the forearms - as muscular and tattooed as a coal miner - but he is not twice the cricketer.

Away from The Oval, it would have been a debatable choice. But on this slow surface he was in his element. He dismissed Dean Elgar for 42, an innings that never really took shape, with a delivery bowled out of the back of the hand leaving the batsman motionless and bowling him through the gate. He later had Parnell caught at the wicket in an over when the batsman had twice nicked him for boundaries through the vacant slip cordon.

As the ball softened, South Africa laboured. Six players in all were bowled, emphasising that this was a pitch that rewarded a wicket-to-wicket attack. JP Duminy held things together until he fell at long off as he went big against the offspin of James Tredwell, who had also accounted for de Villiers as he sought out his favourite flick to deep midwicket.

With Parnell on the card at No. 7, recovery was always liable to be painstaking for South Africa and they never broke free, Anderson wrapping up the innings with the last three wickets in seven balls to leave 20 deliveries unused.

David Hopps is the UK editor of ESPNcricinfo