Chamari was the tenth captain for Sri Lanka women's national cricket team.

[2][3] In November 2023, it was announced that a special dedicated seating zone at the Sydney Cricket Ground would be named after her as the Chamari Bay.

[7][8] She is also the only Sri Lankan woman cricketer to score an ODI century, doing this five times in her career.

[9][10] She holds the record for scoring the most number of ODI centuries and fifties for Sri Lanka in women's cricket history.

[15] Atapattu's 178 not out is the highest Women's ODI score when batting at number three position for Sri Lanka.

[19][20] At 2016 ICC Women's T20 World Cup she scored her maiden T20Is half century against South Africa.

But Atapattu came in charge break the partnership from runout and she bowled Mignon du Preez for a four-ball duck in the same over.

[28] In October 2018, she was named as captain of Sri Lanka's squad for the 2018 ICC Women's World Twenty20 tournament in the West Indies.

[34][35][36][2] In January 2020, she was named as the captain of Sri Lanka's squad for the 2020 ICC Women's T20 World Cup in Australia.

[40] She was the leading run-scorer for Sri Lanka in the tournament, with 154 runs in four matches including one half century.

[41][42] In October 2021, she was named as the captain of Sri Lanka's team for the 2021 Women's Cricket World Cup Qualifier tournament in Zimbabwe.

[43] In January 2022, Atapattu was named as the captain of Sri Lanka's team for the 2022 Commonwealth Games Cricket Qualifier tournament in Malaysia.

[48] Following her performance at the Commonwealth Games Qualifier, she moved into the top 10 of the ICC Women's T20I batting rankings.

[51] In July 2022, she was named as the captain of Sri Lanka's team for the cricket tournament at the 2022 Commonwealth Games in Birmingham, England.

[52] On 10 February 2023, opener of T20 World cup 2023, Athapattu scored her 6th T20I half century against South Africa.

This was their highest partnership for any wicket in Sri Lanka women team surpassing previous record held on first ODI match.

Chamari also put unbeaten 179 run partnership with Nilakshi De Silva, the second-highest stand for the fifth-wicket or lower in the women's game and rescued Sri Lanka from 126 for 4 in the 21st over and successfully chased down the target 302.

Athapaththu's score against South Africa is now the highest while chasing in women's ODIs, bettering Meg Lanning's 152* against Sri Lanka in 2017.

She scored unbeaten 59 runs from 35 balls hitting ten boundaries and one six while chasing down target of 95.

[75] On July 26, 2024 semi final match against Pakistan, Chamari scored vital half century while chasing down target of 141 runs.

[76] On July 28, 2024 final match against India, Chamari played crucial knock by scoring 61 runs from 43 deliveries hitting nine boundaries and two sixes while chasing down the target of 165.

[12] She was named captain of the Sri Lanka squad for the 2024 ICC Women's T20 World Cup.

Five of the nine ODI centuries had been scored in Sri Lanka, and the others in England, Australia, Pakistan, and South Africa, respectively.

Before WBBL, her an unbeaten 178 against Australia in Bristol, helped her to become the first Sri Lankan woman to sign a contract with a franchise-based T20 league.

She represented Yorkshire Diamonds and Loughborough Lightning in the second edition of the Kia Super League in England in 2017.

[2] She was signed by Perth Scorchers for the 2020–21 Women's Big Bash League season and was part of the side's campaign which eventually clinch the title, although she had to leave the tournament halfway due to national commitments.

[92][93][94] In August 2022, she was signed as an overseas player for Guyana Amazon Warriors for the inaugural edition of the Women's Caribbean Premier League.

[95] She returned to Melbourne Renegades during the 2022–23 Women's Big Bash League season, as a replacement for Harmanpreet Kaur.

[97][98] Her inclusion paid rich dividends for the Sydney Thunder as she piled up 511 runs in across 13 innings at an average of 42.58 with a strike rate touching closer to 130, while also doing fine with the ball capturing nine wickets at 25.55 with an excellent economy rate of 6.79[99] and she was awarded the WBBL 09 player of the tournament for her all-round performance both with the bat and ball.