Captain Alastair Cook acknowledged England were second best in their second NatWest one-day international defeat to South Africa.
Their opponents became the first side to top the ICC rankings in all three formats, after Hashim Amla's stellar 150 propelled them to an 80-run win at Southampton's Ageas Bowl - and a 1-0 lead in the series with three matches to play.
Cook said afterwards: "We didn't play very well, in all three aspects. We were up with the run rate but never got that partnership. We've got three games to bounce back. But against Pakistan we lost the Test series and turned it round in the one-dayers. We've got to look at ourselves and stand up and be counted."
Cook hailed the contribution of Amla, saying: "They are playing some good cricket and a lot of credit must go to them. especially Amla. His innings showed us how to play. He's in fantastic form. It's frustrating as a captain but he played beautifully.
"But our dropped catches are slightly disappointing...they're not sticking at the moment. You can't give good players chances like we are doing.
"280 was a really good score but it was gettable. We were up with the scoring rate for a lot of that but you need someone to go on if you're going to chase that down."
South Africa captain AB de Villiers said: "There are still a few things we can work on. It's been a good game for us but there's a long way to go in the series. We've got a lot to prove and many areas to get better.
"Hashim is on fire at the moment, breaking records. We're all proud of him and what's he's achieved - hopefully he can maintain that form for many years to come.
"The wicket played quite well throughout but luckily we kept getting wickets and that kept the pressure on them."
On their progress up the rankings, de Villiers added: "We are quite proud. There's so much cricket around at the moment. We're working towards our ultimate goal - winning the World Cup and staying at number one in the world."