A left-arm orthodox spinner and useful lower-order batsman, Maharaj made his first-class debut at the age of 16 for KwaZulu-Natal in 2006-07. He was promoted to the Dolphins team in 2009-10.

He toured Bangladesh with the South Africa Academy in April–May 2010, taking 13 wickets in the two four-day matches against Bangladesh Cricket Board Academy. He also took 4 for 12 off four overs, opening the bowling, in one of the T20 matches. He played for South Africa A against the touring Bangladesh A team in 2010-11.

His best season with the bat so far has been 2012-13, when he made 481 first-class runs at an average of 48.10, including two centuries. For KwaZulu-Natal against Northerns he made 114 not out off 119 balls and finished off the match by taking 5 for 12.

For Dolphins against Cape Cobras in 2014-15 he took his best innings and match figures to that point: 6 for 58 and 10 for 145. Dolphins won, and he received the man of the match award. He finished the season with 44 first-class wickets at an average of 26.18.

He played for Cuckfield in the Sussex Premier League in 2013, and as Nelson's professional in the Lancashire League in 2015. He was included in the KwaZulu-Natal cricket team squad for the 2015 Africa T20 Cup.

In the first match of the 2016-17 season, playing for the Dolphins against the Warriors, he scored 72 then took 7 for 89 and 6 for 68 in an innings victory for the Dolphins, the first time he had taken seven wickets in an innings or 13 in a match.

In October 2016 he was named in South Africa's squad for their series against Australia. He made his Test debut against the Australians on 3 November 2016 and was instrumental in the collapse of Australian batting in the first innings by picking up three crucial wickets. He was the first specialist spinner to make his Test debut at Perth.

On 10 March 2017, against New Zealand he took his maiden five-wicket haul in Tests. This is only the seventh five-for by a South African spinner in Tests against New Zealand.

In April 2017, he was named in South Africa's One Day International (ODI) squad for their series against England and the 2017 ICC Champions Trophy.^[15][16] He made his ODI debut for South Africa against England on 27 May 2017.^[17]

In May 2017, he was named International Newcomer of the Year at Cricket South Africa's annual awards.^[18] In October 2017, he took his 50th wicket in Tests, during the first Test against Bangladesh.^[19]

In July 2018, during the second test match against Sri Lanka, he registered his best Test bowling figures in an innings of 9 for 124 and also registered the best ever bowling figures in a Test innings by a visiting bowler in Sri Lanka.^[20] He also recorded the best ever bowling figures in a Test innings by a South African in Asia.^[21][22] His figures of 9 for 124 are the second-best bowling figures by a South African in an innings of a Test after Hugh Tayfield and the best Test bowling figures by a South African since readmission to international cricket in 1991.^[23][24] He became the second left-arm spinner, after Rangana Herath, to claim 9 wickets in a test innings.^[25]

In August 2018, he was named in South Africa's Twenty20 International (T20I) squad for the one-off match against Sri Lanka, but he did not play in the fixture.^[26]<