Pretorius smashed 13 sixes and 15 fours as he passed the previous best mark of 175 not out by Chris Gayle for Royal Challengers Bangalore against Pune Warriors in the Indian Premier League in 2013.
Pretorius, 20, was well on course for a double hundred but ran out of overs as the Titans finished their innings on 267 for three.
The left-hander has been in form, with his previous innings a 53-ball 101 for South Africa in a T20 international against Namibia last month.
The Titans' innings total of 267 is also the highest ever in a T20 game in South Africa.
Pretorius has played 17 T20 internationals for South Africa, scoring 427 runs at an average of 25.11 and a strike rate of 150.88. His highest score is that 101 against Namibia.
He has also featured in three ODIs and averages 47.33, and in two Test matches, where he averages 78.33. Seen as a power-hitter, he actually made his international debut in Test cricket, scoring 153 against Zimbabwe in June 2025.