James Magnussen was the fastest qualifier in the heats of the 50-metres freestyle at the Australian Olympic trials on Tuesday but he only had thoughts for the 100m freestyle world record. The world champion was 0.19 seconds outside Brazilian Cesar Cielo’s world record in posting the year’s fastest time of 47.10secs and winning the 100m final on Monday to book his place for the London Olympics. Magnussen, 20, is convinced he will shatter Cielo’s 46.91secs world mark at July’s Olympics and is working on ways to shave more time off his fastest 100m freestyle time so far. ‘Now that I sit back and look at last night’s swim, it’s a bit of a pain in the bum that I got down that close and didn’t get it (world record), but I’m pretty confident I will get it at the Olympics,’ he said. ‘That’s easily the quickest I’ve ever been but I’m just really happy with my skills at the moment, my dive and underwater, it’s improved a lot since the world championships last year that helped me get out in front and swim speeds. ‘Looking at last night’s time I was 0.2 slower on the turn slower than I was at the Shanghai world championships in the relay, that’s all I need right there.’ Magnussen was still quickest in the 50m helter-skelter on Tuesday despite his ‘hangover’ from the previous night’s world record bid. ‘There is a fair lactic acid hangover (from Monday night),’ he said. ‘I swam about 1500m this morning just to try and clear it out. I’ll go and get a massage now and hopefully I’ll be freshen up for tonight’s semis.’ Magnussen was fastest into Tuesday night’s semis in 22.19sec ahead of titleholder Matt Abood (22.44) and Matt Targett (22.47). Former world champion Michael Klim was 10th fastest in the heats of the 100m butterfly, but enough to get him into the semis. Klim, 34, on the comeback trail after four years out of the pool, showed early speed before flagging to finish in 53.45, one second behind Chris Wright (52.45) and 200m champion Nick D’Arcy (52.56).