The Lions' best yet to come
Ackermann, speaking after the Lions' history-making 36-32 win over the two-time Super Rugby champion Chiefs in Hamilton on Saturday, said he was "thankful" for the win.
"The team showed good control when we were ahead and behind," he said of a period in the second half when the Chiefs went up 25-24.
"The players stayed with the game plan and our tight phases were good."
However, he felt there were still too many "soft moments" on defence.
"Although we won, we still have a lot of aspects to work on in attack and defence - which wasn't always good enough.
"We almost lost the game through our own doing.
"Credit to the Chiefs, they just don't give up.
"We will enjoy the win because it is a good win, but the competition is still long and there is still a lot of rugby left.
"We can't get too excited and every week everything starts all over again."
Chiefs captain Sam Cane said there had been too many errors, too many penalties and the side had been dominated too much up front.
"I'm proud of the way we fought back, and we were in it right until the last second of the game, but we shouldn't have to be trying to win a game in the last 10 seconds if we'd managed to get a few of those things I talked about earlier right," he said.
"Like all South African teams they are big up front but I think this Lions team have got a backline to complement them - so credit to the Lions, they've come all the way from Japan so it's a good start to their tour, they're a quality side so well done to them," Cane added.
Lions skipper Warren Whiteley said it was difficult to put his feelings into words.
They had so much respect for the Chiefs and what they had achieved in Super Rugby.
"I'm just so proud of the team today, it was a fantastic performance and I would like to thank the Chiefs," he said.
"They came at us and put so much pressure on us and it went right to the death. We managed to pull it off in the end but I am really proud of the team.
"I must give credit to our backs today, we worked really hard during the week, we weren't happy with last week's performance so we worked really hard on our strength to spread from side to side and I think it worked.
"At times the Chiefs really put pressure on us but luckily our set piece managed to hold up. It's a first for us so it's difficult to put into words."
It didn't get any easier for the side, he said, because they play the Highlanders next week in Dunedin and they knew they would have to be better against the defending champions.
"They're definitely going to come for us so it is back to the drawing board on Monday, we'll enjoy the win but definitely keep our feet flat on the ground," he said.