Jack Sock is through to the second round of the Dallas Open after prevailing 7-6 (7-2) 4-6 6-4 in a tough opening test against Ilya Ivashka.

Belarus' Ivashka is ranked over 50 spots higher than Sock, but he is in some torrid form, with Monday's loss his sixth in a row.

Sock snapped his own three-match losing streak, and he did so despite committing 10 double faults, coming up clutch in break point situations by saving 15 of Ivashka's 18 opportunities.

Meanwhile, 21-year-old Argentinian Juan Manuel Cerundolo booked a meeting with compatriot and top seed Diego Schwartzman after beating Pablo Andujar 6-4 1-0 (retired) in the first round of the Cordoba Open.

The rising Cerundolo now boasts a 13-1 record since the beginning of the new year, while it was Andujar's fifth loss in a row.

In an all-Spanish showdown it was Bernabe Zapata Miralles emerging victorious 6-7 (6-8) 6-3 7-5 against Roberto Carballes Baena, while Serbia's Dusan Lajovic defeated Peru's Juan Pablo Varillas 7-6 (7-3) 6-3.

The last match of the night saw Italy's Luciano Darderi handle France's Hugo Gaston 6-4 6-3, with Darderi now set to face fourth seed Sebastian Baez.