Pegula broke Romania's Ruse twice in each set on the way to a 6-3, 6-2 triumph, but it was less straightforward than the score indicated as the 32-year-old veteran felt the weight of playing first on the cavernous show court.

"Oh yeah, I was so nervous today, always the first round of a slam," said Pegula, the 32-year-old who is the highest ranked American either the men's or women's draw in the final Grand Slam of the year.

"It's an amazing honour," she said of being given the first match on Ashe. "It's an honour to hold that title, walking out onto Ashe opening day, first match, it's amazing."

Pegula is chasing her first Grand Slam title. She came closest with a runner-up finish to Aryna Sabalenka at the 2024 US Open, and she fell to the Belarusian in the semi-finals last year.

Pegula saved the only break point she faced, but her nerves showed as she converted just two of her 14 break point chances in the opening set.

That was enough, and she was an efficient two-for-four on break opportunities in the second. She gave herself triple match point with a crisp forehand winner to the corner and after Ruse saved two with booming serves secured the win when the Romanian put a forehand into the net.

With the first round now spread over three days, Pegula was looking forward to a couple of days off with a confidence-boosting win under her belt.

"I get to sit around the site and watch everybody else freak out for the next two days," she said.