Bernard Tomic progressed to the second round of the Chengdu Open as the Australian came from a set and a break down against Bradley Klahn to record his first tour-level win since Wimbledon.

The 25-year-old Australian lost the first-set tie-break only to win the next breaker and then take two games on Klahn's serve in the decider to seal a 6-7 (6-8) 7-6 (7-3) 6-2 victory.

Gael Monfils, seeded fifth in Chengdu, or Lloyd Harris will be Tomic's last-16 opponent.

Joao Sousa claimed his 25th victory on the tour this year by beating Tim Smyczek 7-6 (7-1) 6-7 (7-9) 6-3 having initially failed to convert his match point in the second set.

Eighth seed Andreas Seppi is out of the Shenzhen Open after Albert Ramos Vinolas claimed a 6-7 (5-7) 7-6 (9-7) 6-3 success.

Viktor Troicki overcame Guillermo Garcia-Lopez when the Spaniard retired, while Pierre-Hugues Herbert, Yoshihito Nishioka and Cameron Norrie all claimed round-of-32 wins too.