That's how it seemed to Zhang, who offered insight into his bond with Ma in an exclusive CNBC interview that aired Friday. That relationship is in focus as the CEO is preparing to succeed Ma as the chairman of the Chinese e-commerce giant.
In his first TV interview since the succession move was announced, Zhang revealed how he met up with Ma to come up with new ideas for the firm and times when he clashed with the outgoing chair.
Both leaders met regularly for tea but discussed business as well as "experiences."
"He just shares what you think, and it's something relevant to business, something not relevant, about people, about your experience. So it's more like brothers and you haven't seen each other for some time and you catch up for coffee," Zhang told CNBC.
He described his leadership style as "complementary" to Ma's and described how the two worked together on new ideas for the business. And if Ma repeated his idea three times to Zhang on separate occasions, it was a very serious suggestion.
"In the past few years he spent a lot of time in the air, I spent most of the time in the campus. He gives me a lot of ideas out of the box ... many ideas maybe you will be surprised to hear that at the first time, but if you think again and again, you will find some opportunities there," Zhang said.
"He has a lot of ideas. So as he always said, and this is also my discipline, which is when I hear his ideas for the first time, I will listen, I will take the ideas, and I will ... (think) about this. But if he repeated his ideas ... at least three times, then I will take it very seriously. I think this must be his very serious ideas."
Despite the two working closely together, there were of course, disagreements. Ma had strong opinions on his ideas, but Zhang was always open to debate.
"I think if you have some different opinions, I think you have voice up, you have to let him know ... this is your view. But I think the most important thing is that you have to express this in a very clear way. And he maybe will argue. Actually, I know that he hears what I said and maybe he still insists. You know that he's very confident, self-confident of his ideas. He will insist his ideas, but he will listen and he will think and maybe he will change," Zhang said.
Earlier this year, Alibaba announced that Zhang would move into the role as chairman of the board in September 2019.
Zhang said that had been planned "for a long time."
"He tried to convince me to accept this, and we had several times a conversation, but I understand why he decided this, it's all about the future of Alibaba," the CEO said.
While Ma has been the public face of the company for a long time, Zhang, who does not often appear in front of media, has been a key figure behind the company's transition into mobile and its so-called New Retail strategy.
He joined the company in 2007 as chief financial officer of Taobao Marketplace and general manager of Taobao Mall, which later became Tmall. Both are key products in Alibaba's e-commerce portfolio. He was the architect of the company's huge annual shopping event called called Singles Day. He's also been a key driver of Alibaba's online-to-offline strategy, which looks to merge online shopping with brick-and-mortar stores.
Zhang is viewed by analysts as a safe pair of hands because of his achievements at the company, but reaction to the succession news has not been uniformly positive. Alibaba's stock dropped on the day of the news announcement and some media outlets ran articles saying Ma was a tough act to follow.
But Zhang said he just focuses on doing the best job he can and tries to "forget about the pressure."
"Try everything you can for the best results — and of course you need a little bit of luck," Zhang told CNBC.