Katie Boulter battled into the second round of the Hong Kong Open with a straight-sets victory over Viktorija Golubic, despite an incident that "got under my skin", according to the British No 1.

Boulter was twice broken when serving for the match in the second set, having complained to the umpire when up 5-2 after a point was not replayed despite her being distracted by a noise from outside the court.

She ultimately triumphed in a tiebreak to take the match 6-2 7-6 (7-2), clinching a fourth win in five following on from reaching the semi-finals in Japan Open last month that saw her reclaim top spot from Sonay Kartal as British No 1.

Boulter, ranked 49th in the world and seeded eighth at the tournament, had got the better of Golubic in Osaka two weeks ago and repeated the feat in her Hong Kong opener.

She was broken early on by the Swiss but hit back to win eight games in a row to take the first set and control the second.

A superb passing winner at the net helped Boulter move 4-1 up before she squandered match point on Golubic's serve and was then broken twice, but the 30-year-old held her nerve to first force a tiebreak and then take it to reach the last 16.

"It was interesting," Boulter said of her second-set wobble. "I was playing some really good tennis. I feel like I should have closed it out but a couple of things happened.

"There was a little bit of interesting judgement which got under my skin a little bit and, usually, I'm pretty good at batting it off but I was a little tired.

"It's end of season and it seemed to get to me but lesson learned, I managed to get over the line."

Boulter plays play American Claire Liu in the next round.