(Photo credit: Geoff Burke-Imagn Images)

It's hard to believe that 21-year old Coco Gauff is competing in her seventh Australian Open.

But the No. 3 seed is doing just that and, despite some serving issues early, defeated Uzbekistan's Kamilla Rakhimova 6-2, 6-3 in one hour, 39 minutes in warm Melbourne conditions on Monday.

Gauff reached a pair of milestones with the victory. She recorded her 75th match victory in a Grand Slam event and her 250th win on the WTA Tour.

Gauff produced six of her seven double faults in the opening set. She converted six of 14 break chances and saved five of seven break points.

'I think both of us were struggling on the far side,' Gauff said. 'The sun is right there, which I know for every time I play first in the day here, that's just how it is.'

Gauff's second-round foe will be Serbia's Olga Danilovic, who took out 45-year-old Venus Williams in three sets on the first day of the tournament.

No. 2 seed Iga Swiatek of Poland survived an early challenge in a 7-6 (5), 6-3 win against Chinese qualifier Yuan Yue. The six-time major winner trailed 5-4 in the opening set before rallying to collect her 25th consecutive first-round win at a Grand Slam tournament.

'I think she played well,' Swiatek said of her opponent. 'She used the opportunities that I gave her a bit. Yeah, was kind of playing pretty strong from the forehand side. She was for sure going for her shots, playing fast.'

No. 8 Mirra Andreeva of Russia overcame a slow start for a 4-6, 6-3, 6-0 defeat of Croatia's Donna Vekic. Russian No. 23 seed Diana Shnaider also rallied for a 2-6, 6-3, 6-3 defeat of Czech Barbora Krejcikova.

No. 13 Linda Noskova of the Czech Republic, No. 14 Clara Tauson of Denmark, No. 17 Victoria Mboko of Canada, No. 19 Karolina Muchova of the Czech Republic, No. 21 Elise Mertens of Belgium and No. 25 Paula Badosa of Spain all won in straight sets.

After Gauff's early victory, it was a mixed bag for the rest of the American contingent on Monday.

No. 4 seed Amanda Anisimova cruised to a 6-3, 6-2 win over Switzerland's Simona Waltert and No. 6 Jessica Pegula breezed to a 6-2, 6-1 victory against Russia's Anastasia Zakharova. No. 29 Iva Jovic eliminated fellow American Katie Volynets 6-2, 6-3.

No. 15 Emma Navarro and No. 27 Sofia Kenin made quick exits, however. Navarro dropped a 3-6, 6-3, 6-3 decision to Poland's Magda Linette, while Kenin, the 2020 Australian Open champ, fell to compatriot Peyton Stearns, 6-3, 6-2.

Unseeded Americans Ann Li and McCartney Kessler beat Colombia's Camila Osorio and Emiliana Arango, respectively. Li triumphed, 6-4, 6-7 (5), 7-5, while Kessler earned a 6-3, 6-2 victory. Wild card Elizabeth Mandlik fell to Hungary's Anna Bondar, 6-0, 6-4.

Also advancing to the second round were Croatia's Petra Marcinko, Poland's Magdalena Frech and Linda Klimovicova, Russia's Oksana Selekhmeteva, Japan's Moyuka Uchijima and Australia's Storm Hunter, Ajla Tomljanovic and Priscilla Hon.

--Field Level Media