New York, Aug 30 (IANS) Daniil Medvedev says he is not feeling the "extra pressure" of being the defending US Open champion after easing to a 6-2, 6-4, 6-0 victory over Stefan Kozlov of the US in the first round.

The Russian won the first grand slam title of his career last year when he defeated Novak Djokovic at Flushing Meadows, and started his defence in dominant fashion on Arthur Ashe Stadium on Monday, reports DPA. The world number one broke American outsider Kozlov eight times in a one-sided encounter in New York, in which he struck 37 winners and committed 19 unforced errors.

Top seed Medvedev does not feel burdened by being the man who won the final major of the year in 2021.

"(There is) a little bit (of) extra pressure (in being the defending champion)," he stated, "But mostly, I don't feel it, to be honest. Probably the only pressure is I know if I'm not going to play good here, for whatever reason... I will not care that I won it last year, I will just be disappointed that this year did not work out my way."

Medvedev will face Arthur Rinderknech of France next on Wednesday, after the Frenchman defeated his compatriot Quentin Halys in four sets on day one.

Meanwhile, former US Open champion Dominic Thiem has been bundled out at Flushing Meadows in the first round by Pablo Carreno Busta 7-5, 6-1, 5-7, 6-3.

The Austrian, who was back to defend his 2020 title after missing last year due to a wrist injury, was no match for the 12th-seeded Spaniard, despite coming in with a 7-0 head-to-head record.

Four-time Grand Slam finalist Thiem has struggled for the past 14 months, with a mix of injury and form, only gaining entry at the US Open with a wild card.

Thiem is now ranked 211th in the world and has a 9-10 record this season, albeit with an improved past two months.

Former world number three Thiem had waited 426 days between ATP Tour level wins, when he triumphed at the Swedish Open in July this year.

Carreno Busta, who won in Montreal earlier this month, won in three hours and 18 minutes, rallying back from a 2-4 deficit early to peel off 10 of the next 11 games and claim a two-set lead.

Thiem responded in the third set by breaking in the second game, with Carreno Busta committing more unforced errors, but the Austrian could not maintain the pressure in the fourth.

The Austrian hit 44-31 winners but was not helped by unforced errors (54-32), while his first serve percentage was down at 59 per cent, winning only 58 per cent on his first serve.