Britons Jamie Murray and Neal Skupski kept alive their hopes of reaching next week's ATP Finals with a first-round win at the Sofia Open.
The Britons are chasing the final spot in the doubles event at the prestigious end-of-season tournament in London.
They beat Slovakia's Igor Zelenay and India's Divij Sharan 6-3 3-6 10-6 in the Bulgarian capital on Monday.
Murray and Skupski must reach the final here to have a chance of qualifying for the ATP Finals, which start on Sunday.
The pair need to overtake Jurgen Melzer and Edouard Roger-Vasselin, who currently occupy the eighth and final qualifying place. If top seeds Melzer and Roger-Vasselin were also to reach the final in Sofia, Murray and Skupski would not be able to qualify.
The British second seeds face Alex de Minaur and David Vega Hernandez or Radu Albot and Artem Sitak next.