South African record holder Prinsloo scraped into Thursday evening’s 100m freestyle semi-finals in a time of 55.04 seconds, which was just 0.07 seconds off her national record set in March last year.
“I’m happy that I made the semi-final for tonight and it’s nice to see that I’m close to my record as I have not done the amount of training like I used to,” she said.
Malawian-born Cate Campbell, who lives and swims for Australia led the qualifiers from American Missy Franklin, who has already won three gold medals in the Palau Sant Jordi.
Murray, meanwhile, qualified for the men’s 200m backstroke semi-final with a time of 1:59.19, securing him the final place in the semi-finals.
Murray, who swam in the same heat as American star Ryan Lochte, said that it was his goal to some time swim next to him in a final.
“I did not know I was in the same heat as Lochte as I was very focused,” Murray said.
“But I am not happy with the time as I felt comfortable and it felt like I would go faster. But I have another chance tonight.”
American swimmer Tyler Clary is the fastest qualifier, followed by Great Britain’s Craig McNally and Lochte.
Prinsloo and Murray said they had gained strength from the team’s outstanding performance on Wednesday night, when Chad le Clos won gold in the 200m butterfly, while Cameron van der Burgh and Guilio Zorzi took gold and bronze respectively in the 50m breaststroke.
“There’s a great vibe within the team and everyone is really focused and wants to do well. The momentum to ride on is huge after having the three guys medal last night,” Murray said.
The other South African in action in the heats on Thursday, Tara-Lynn Nicholas, 18, failed to advance in the women’s 200m breaststroke.