Shahjahan Khan has been on Tour since 2011, but started making real strides up the World Rankings over the last couple of seasons.

The American had to wait three years before he made his first final on Tour, doing so at the Colony Ford Lincoln National Squash Academy Open, and that would become his first title as a professional a year later, as he beat Arthur Gaskin in the final in 2015.

He reached the semi-finals of the Samson Seattle Open and the 6th Parco Roshan Khan Open in 2016, but had to wait until 2018 before he made another final. That c game at the Wakefield PSA, where he lost out to Juan Camilo Vargas.

Khan claimed his second title later that year, beating Henrik Mustonen to win the Alliance Fabricating Ltd. Simon Warder Memorial Prostate Cancer Open, and he also had semi-final appearances at the 13th CNS International Squash Championship, Life Time Atlanta Open and Qualico Manitoba Open in the 2018-2019 campaign.

At the end of 2019, the American took two more victories, winning the Celestino Martinez Memorial Tournament and the Open International Niort Venise Verte. He made the semis of the Qualico Manitoba Open for a second straight year, and broke inside the top 60 in the World Rankings for the first time at the end of 2020.

Khan won his fifth Tour title in his first outing of 2021, claiming the victory at the Life Time City Centre Men’s Open Presented by NH Specialists before then also making the last 16 of the Squash on Fire Open. The American then broke into the third round of a Platinum event for the first time, doing so at the CIB Egyptian Open.

He also made the last 16 of the Challenger 30 level Cleveland Skating Club Open, before making it into the quarter finals of the Malaysian Open Squash Championships. Another appearance in a final came at the Wakefield PSA, before he started 2022 by reaching the second round of the Gold level Houston Open, and as a member of the world's top 40.

He then broke into the world’s top 30 early on in 2022, thanks to making he quarter finals of the Bronze level Karachi Open Squash Championships. A string of last 16 appearances followed, including at the Allam British Open and the QTerminals Qatar Classic. Another quarter final, this time at the Oracle NetSuite Open on home soil, along with a last 16 appearance in Kuala Lumpur, rounded out 2022.

The American No.1 made the last 16 of both the Sturbridge Capital Motor City Open and the Oxford Properties Canadian Men’s Open before reaching the last four of the Challenger 20 level Cannon Kirk Gillen Markets Irish Squash Open later in the campaign.