London - Chad le Clos believed he would need to swim faster than the national record he set on Monday if he wanted to win a medal in the men's 200 metres butterfly event at the London Olympic Games.
The versatile South African swimmer progressed to Tuesday night's final in style as he clocked a national record of one minute, 54.34 second (1:54.34).
"I definitely think I need to go faster if I want to win a medal," Le Clos said.
"I'm pretty sure that there will be at least three or four guys that could go under 1:54."
He finished second behind Takeshi Matsuda of Japan in the faster of two semi-finals on Monday, while American Michael Phelps won the other semi-final in 1:54.53.
Le Clos hoped to replicate his performance in the semi-final in an effort to secure South Africa's second medal at the London Games.
"I'm just going to do it like I did it today (Monday)," he said.
"I'm going to go out there and make sure I am in the race and hopefully we'll have a race in the last 25 metres. It should be good."
Improving his personal best had given him a boost ahead of the final.
"I'm happy I broke my PB by almost a second," Le Clos said.
"That is the main thing for me, coming in here and getting my times down and proving to myself that I can handle the big stage."
The 20-year-old finished fifth in the men's 400m individual medley, his maiden Olympic final, on Saturday.
"To make the final was vital and I didn't expect to come top five, but that is an even bigger boost," he said.
"I think that helped me for this race (the butterfly semi-final)."
Le Clos, tipped to win a medal on his Olympic debut, believed he had an opportunity secure a podium place in the 200m butterfly final -- perhaps his best event.
"I could come eighth or I could get a medal," he said.
"It is a very close final and there are some really great swimmers out there.
"I'm just going to go out there and I will race 100 percent.
"When I finish that race I will be broke, I will give it my all and I guess you can't ask for more than that."