The German put on a strong showing at Sepang to score his first points with Sauber after finishing in eighth position, ahead of the McLaren of Sergio Perez and right behind the Lotus duo.
Hulkenberg had been unable to start the season-opening race in Australia because of a car problem.
Kaltenborn praised Hulkenberg's fighting spirit throughout the race.
"Of course you can see it's tough for us to keep certain cars behind us but I think that Nico did a very good job and fought as well as he could. I think he showed his skills and proved the reason why we've taken him," said Kaltenborn.
"We see in him a very efficient driver and a fast driver. He made use of what he could with the car and I was quite impressed that he did try to hang on that long to the Lotus.
"He fought a lot but still he could hang on to them, which was very good."
Sauber enjoyed its strongest season to date last year, finishing in sixth position in the standings after four podiums.
The Swiss squad has so far been unable to start a race from the top 10 this year, but Kaltenborn remains bullish about the potential of its car.
"It's too early to make any kind of call into any direction," she said. "For us we can clearly say that we are convinced in the potential of the car.
"Of course we lost out on collecting all of the data we could in the first race.
"Importantly now with the data we've collected, we analyse it properly at home because we need an understanding of that to see where we can still improve."
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