Cape Town - The Proteas ended up losing the second Test against England at Newlands by 189 runs on Tuesday, but the more telling statistic was that they fell just 50 balls short of what would have been a famous save.
Starting day five on 126/2 needing an unlikely 438 for victory, the Proteas quickly went on the defensive in their efforts to secure a draw that would have been a massive result in the context of the series.
While they ultimately fell short, it was not without resilience as the likes of debutant Pieter Malan (84 off 288), Rassie van der Dussen (17 off 140) and Quinton de Kock (50 off 107) made things interesting for most of the day, with the draw the likeliest result for some time.
Ben Stokes (3/35) was the man who rolled through the South African lower order to seal the deal for the visitors and level the series at 1-1 with two Tests to play, but Du Plessis was incredibly pleased by the resilience shown by the batters on a day where they started as comfortable underdogs.
"I'm extremely proud of how we fought. You never want to lose Test matches ... but the challenge that we put to our group last night and this morning was that we would fight with everything we've got," Du Plessis said.
"We wanted to make England do everything and anything to beat us, and they have. They've thrown the kitchen sink at us and, unfortunately, towards the end of the day there needed to be a loser.
"It was a fantastic five days of Test cricket where both teams were on top and some sessions were on par. Probably for the majority of the Test match England were better than us."
Du Plessis himself, though, continued his poor run of form - his scores in the series read 29, 20, 1 and 19 - when he played a sweep shot to be caught at square leg on Tuesday off the off-spin of Dominic Best at a crucial stage of the game.
The skipper accepted responsibility for what he labelled a "mental error".
"To sweep it in the middle of the two (square leg and midwicket) was a mental error," he said.
"Generally, when you have that many guys around the bat, you try to manipulate the field a bit and get them to spread out, and then go about your business as normal again.
"In that situation all we needed was for me to drop anchor. I suppose the same with Quinny (De Kock).
"We were going really well there, and it felt like we were in control, so probably the same for him and to give them two wickets on a wicket that was still good was probably going to be the difference."
Despite the loss, Du Plessis felt that the Proteas had shown improvement, particularly in their batting department and after they were humiliated 3-0 in September's Test series in India.
"If you look at a batting unit point of view from where, two months ago, we were very weak mentally in India and exploded quickly, today we didn't," he said.
"It's just about improving as a young Test team and making sure that you are getting better.
"Sometimes you will still lose while you are improving, and that was the case for me in the last two days.
"As a batting unit, we can take confidence from guys like Pieter Malan and the way he played and Rassie dropping anchor and doing what the team needs.
"There were some real good signs for us from a batting point of view in this Test match. Yes, there is still room for improvement, but I do feel that we are improving."
The third Test will see the sides move to Port Elizabeth.