Esterhuizen led the Sharks to a tense 28–23 victory over English heavyweights Saracens in round two of Pool 1 of the Investec Champions Cup at Kings Park.
Taking charge for the first time following the departure of John Plumtree, Pietersen reflected on Esterhuizen’s journey through the ranks…
"I can remember Andre like yesterday when we made his debut. I was center and he came on a wing in New Zealand against the Hurricanes, we played a lot of games together. I am unbelievably proud of him, he is a natural leader," said Pietersen.
The win came at a crucial moment for the Durban-based side, who arrived under significant pressure after a heavy 56–19 loss away to Toulouse in their opening Champions Cup fixture.
That defeat followed a run of mixed results in the United Rugby Championship, form that ultimately preceded the coaching change.
Pietersen admits the build-up to the Saracens clash was demanding, describing the week as a severe test, but says the players responded positively to the challenge in front of a home crowd.
The encounter was played in difficult conditions, with heavy rain and a swirling wind making execution unpredictable throughout the match.
Despite the elements, the Sharks dug deep to secure the result, a win that keeps them firmly in contention in a Champions Cup pool that has opened up following Glasgow Warriors’ surprise victory over Toulouse.
Pietersen pointed to rugby’s unpredictability but reserved special praise for the resilience and unity shown by his players in tough moments.
"That's a game of rugby it is unpredictable and sums up what I asked the whole week, that can we play for 80min'
But I saw the character of the team, you could see how much it meant for them in the changing room," added Pietersen.
The Sharks are set to host the Bulls in a United Rugby Championship South African derby. Pietersen says victories like the one over Saracens are vital, not only on the log, but for belief and confidence, as the team builds momentum heading into another demanding fixture.
"A win is always important, it gives you the confidence going into the next game. You know the Bulls - it is not going to be easy they are also desperate. It will not be easy going into next week," he expressed.
The Sharks’ remaining Investec Champions Cup pool fixtures see them travel to face Sale Sharks on 10 January, before closing out the group at home against Clermont on 17 January.