It wasn't a totally smooth ride - the No.5-seeded Black and Mirza led 4-2 in the first set and had a set point while serving for the set at 6-5 - but the No.1-seeded Hsieh and Peng never stopped fighting, rallying to take the opening frame in a tie-break and cruising from there to prevail, 76(5) 62.
They were asked afterwards whether the perfect finals record was on their minds on the court.
"We didn't think about it," Peng said. "Every time we just try to fight every point. Like today, first set we were down, it was really windy, and they're a really good doubles team. Cara Black has lots of experience in doubles, especially, and they were giving us a lot of pressure. So we're happy we won."
Hsieh and Peng's 11 WTA doubles titles include one in 2008 (Bali), three in 2009 (Sydney, Rome and Beijing), five in 2013 (Rome, Wimbledon, Cincinnati, Guangzhou and the WTA Championships) and now two in 2014 (Doha and Indian Wells). They're currently the No.1-ranked doubles team in the world.
But they aren't letting all of that change who they are, or how they feel when they're on the court.
"We're the No.1 team, and people may know us more now, but we still feel the same as before," Peng said. "All of this is nice because it helps us become more confident and believe in ourselves more on the court, and we're more motivated now too, but nothing has changed. We're still the same people."
"We've known each other a very long time," Hsieh said. "Sometimes we don't practice together - like at Wimbledon we never practiced together - but every time we go on court together, we try every point. If she misses a shot, I give her support. When I miss, she supports me. It's very important in doubles.
"When we get into a final, we don't think, we just try every point. This is the key for us."