Kevin Pietersen had mixed emotions after scoring the fastest one-day ton by an England batsman but still losing to South Africa in East London.
He said: "I'm not too happy. Personally it is fantastic but I'm not happy to miss victory by eight runs.
"I can't complain personally. We said if we were chasing a massive total we would take it slowly and keep wickets in hand and have a go at the end.
"Unfortunately, I couldn't pull it off today but we can still tie the series."
Pietersen picked up an injury during South Africa's innings but he batted through it with slight discomfort and hoped to be fit for the next match.
"I hurt my hamstring in the field. Hopefully it will be OK but I'll sort something out with the physio," he added.
He needed just 69 balls for the century, with four sixes and seven fours.
It was equal ninth fastest in the all-time records, matching Indian star Virender Sehwag's best innings.
England captain Michael Vaughan paid tribute to both Pietersen and his own opposite number Graeme Smith, who like Pietersen now has two centuries in the series.
"Kevin played a tremendous knock and got us nearly over the final fence," said Vaughan.
"Graeme Smith's knock was outstanding, and Kemp hit the ball very hard and far. It was very tough to control him."
Justin Kemp had struck an eye-watering seven sixes, his 80 runs coming off just 50 balls.
Smith, who carried his bat for an unbeaten 115, said: "It's been superb.
"We came here to do a job that we needed to do, so now we can move on to Durban.
"It was crucial to keep building on our performances. We have one or two areas we can work on, but Justin played superbly at the death and our bowlers did a fine job.
"It was difficult at the end, the ball was wet and it wasn't easy to grip it.
"I thought the bowlers did their job. We're starting to gain confidence in a lot of areas and we're playing some very good cricket."
The series concludes with games in Durban on Friday and Centurion on Sunday.