When he stepped onto the starting block at the OCBC Aquatic Centre, Mikkel Lee would break the nervous silence among his competitors with a deep grunt.

But that was not the only thing he broke yesterday; the Secondary 4 student from Anglo-Chinese School (Independent) rewrote two B Division records at the schools swimming championships.

Mikkel first powered to victory in the 50m butterfly final in 24.73sec, bettering the 25.16 he clocked in the heats on Tuesday.

The 16-year-old then set a meet record of 1min 44.76sec with team-mates Ernest Ching, Nicholas Cheong and Jonathan Tan in the 4x50m medley relay, rewriting their seniors' 1:45.81 set in 2016. Raffles Institution (RI) finished second (1:49.48) and the Singapore Sports School (SSP) were third (1:52.60).

"I haven't exactly tapered before this competition, so knowing that I could come close to my personal best was really encouraging," said Mikkel, who equalled his personal best in the 50m fly yesterday.

Listening to music and setting personal goals are part of his pre-race routine.

"I listen to a lot of rap music, those with strong bass to get my heart pumping and blood flowing," said the quadruple Asean Schools Games gold medallist.

"Before I race, I always ask myself what exactly I want to achieve and that really keeps me focused and determined."

In the B girls' 4x50m medley relay, Methodist Girls' School (MGS) pipped defending champions Raffles Girls' School (RGS) to the title.

The quartet of Chelsea Khoo, Grace-Marie Low, Natalie Ho and SEA Games bronze medallist Gan Ching Hwee touched home in 2:01.21 to finish ahead of RGS (2:03.73) and SSP (2:04.74).

MGS' Chelsea, who swam the backstroke first leg, said: "We knew it was going to be a tough fight, but we told each other that if we try our best, we can do well."

With one day to go, MGS top the standings in the girls' B Division while RGS and RI are ahead in the C and A Divisions respectively. Traditional powerhouses ACS(I) leadall three boys' divisions.