Borna Coric and Bernard Tomic booked their places in round two of the Shanghai Masters as the tournament's main-draw action got under way on Sunday.
Teenager Coric - a winner on the ATP Challenger Tour last month - overcame a major wobble in the second set to defeat Alexandr Dolgopolov 6-3 1-6 7-6 (7-5).
Tomic also sealed his victory in a tie-break, but only needed two sets as he recorded a 6-3 7-6 (7-3) victory over experienced Spaniard Fernando Verdasco.
Sunday's opening match was a topsy-turvy encounter, with Coric claiming the sole break in the first set before losing five games in a row at the start of the second.
When Dolgopolov broke again for a 2-1 lead in the decider, the Ukrainian looked set to book a potential meeting with 14th seed Marin Cilic in round two.
However, Coric hit back to pull level and then came from 3-1 down in the tie-break, accepting his second match point.
Tomic did not face a single break point as he saw off Verdasco, whose own serve rarely came under threat.