India lost the rain-hit match by 48 runs via Duckworth and Lewis method to allow South Africa level the series 2-2 last night.
Dhoni acknowledged the smart batting by young Virat Kohli but did not hide his disappointment over an otherwise poor show by other batsmen.
"It`s (Kohli`s batting) a big positive for us. It`s good for us at number three. He has carried through the innings but the other batsmen also need to chip in. The middle-order has not clicked and it`s true for South Africa also," Dhoni said after the match.
Dhoni conceded that India let slip the game despite dominating it in the early part of the South African innings when the hosts were tottering at 118 for five.
"We tried our best. We used most of the bowlers and as a captain it`s more pressure when you have to get that one more wicket. Every time it does not go your way," he said.
"We fancied our chances but it becomes difficult with Duckworth and Lewis method when you are batting second. And the approach at the start has been conservative in this series, not to loose too many wickets in the beginning. So when D/L method comes after the start of the second innings, it becomes tough," he added.
About the series deciding fifth match in Centurion tomorrow, Dhoni said, "It will be interesting. The team that handles pressure better will win."
J P Duminy, who was declared man-of-the-Match for his fighting 71-run unbeaten knock, was pleased with his effort.
"The plan was to take it as deep as possible and got a defendable total in the end. We were not scoring boundaries but the run-rate was between four and six. When we reached near 45 overs, we knew we will get 250 but we managed to cross that. Very pleased with that," the South African left-hander said.
Winning captain Graeme Smith was all praise for Duminy, who batted through the innings to lift the team from 118 to five to 265 for seven in the end.
"It was excellent effort from him (Duminy). He showed a lot of determination to get us to that total. It was nice to win. And it`s big Sunday coming up. The two teams have a lot of respect for each other and it`s been so competitive."