Co-World No.1s and doubles partners Martina Hingis and Chan Yung-Jan smiled for the camera as they commemorated their rise to the top of the rankings.
They are the 12th pair to jointly hold the top spot.
Chan joined her partner as World No.1 this week as she became the second woman from Chinese Taipei to achieve the milestone.
Chan won her maiden Grand Slam title this year with Hingis at the US Open, and the team are competing at the BNP Paribas WTA Finals Singapore presented by SC Global.
Hingis returned to No.1 at the start of October having previously held the top doubles ranking for 66 non-consecutive weeks. She was the youngest-ever doubles No.1 at the age of 17, on June 8, 1998.