The World Co-No.1s haven't lost a match since August, and were always in control during the 63 minute win over the Kichenoks, who could only break serve once to Santina's four. Hingis and Mirza hit a combined 18 winners to just 11 unforced errors, and won 72% of their first serve points.
Up next for the top-ranked team is the unseeded but potentially dangerous pair of Svetlana Kuznetsova and former doubles No.1 Roberta Vinci, who eased pass a pair of Aussies in Jessica Moore and Storm Sanders, 6-0, 6-3.
The Indo-Swiss duo has bagged 11 titles so far in their very successful partnership - including the first two tournaments of 2016 in Brisbane and Sydney - and are a mere 12 wins away from tying Jana Novotna and Helena Sukova's 1990 record of 44 wins in a row.
No.2 seeds Chan Yung-Jan and Chan Hao-Ching eased into the third round with a two-set win over Kateryna Bondarenko and Olga Savchuk, while No.3 seeds Kristina Mladenovic and Caroline Garcia and No.7 seeds Andrea Hlavackova and Lucie Hradecka also emerged in straight sets.
No.5 seed Elena Vesnina and new partner Anastasia Pavlyuchenkova also had a solid second round outing on Saturday, defeating Ysaline Bonaventure and Raluca Olaru in straight sets, 6-1, 6-2. The pair will next face Pavlyuchenkova's former partner Alla Kudryavtseva, who recently paired with resurgent American Vania King. King and Kudryavtseva were ruthlessly efficient in upsetting No.11 seeds Samantha Stosur and Yaroslava Shvedova - King's former partner, with whom she captured the 2010 Wimbledon and US Open tropies - 6-1, 6-4.
The biggest upset of the day came from giant-killer Barbora Strycova; fresh from upsetting No.3 seed Garbiñe Muguruza in singles, the Czech veteran paired with Mirjana Lucic-Baroni to take out No.6 seeds Raquel Atawo and Abigail Spears, recovering from a set down to win, 6-7(4), 6-2, 6-1.
Mirza is also the top seed oin mixed doubles; she and partner Ivan Dodig cruised past Aussies Ajla Tomljanovic and Nick Kyrgios, 7-5, 6-1. No.2 seed Bethanie Mattek-Sands shook off the disappointment of falling in her second round women's doubles match on Friday by pairing with Bob Bryan to defeat Jessica Moore and Marc Polmans, 6-2, 6-1. The love match between Daria Gavrilova and boyfriend Luke Saville was less successful, falling to Shvedova and Aisam Qureshi, 6-4, 7-6(5).