With the big black swimsuit permanently shelved, Grant Hackett opened the post-Ian Thorpe era with a less than imposing victory in the 400m freestyle.

The Dolphins skipper wasn't happy with his opening performance at the national titles as he narrowly held off the resurgent Craig Stevens by two thirds of a second at Brisbane's Chandler Aquatic Centre.

Hackett, competing at the selection trials for the first time since shoulder surgery, proved that a red suit does not make him go any faster with a sluggish time by his standards of three minutes 46.00 seconds.

The distance supremo has declared his objective of chasing down Thorpe's world record of 3:40.08sec by the time the 2008 Beijing Olympics roll around.

He was well off the pace, his swim ranking him fourth in the world this year behind American Klete Keller.

However Hackett has not fully tapered for the eight-day meet as he attempts to be at his fastest for next year's world championships in Melbourne.

"I look at that as a pretty slow time for myself so I will be hoping to cut that down by a few seconds before (the) worlds," Hackett said.

But it was a great night for Stevens, who has also lived heavily in Thorpe's shadow for very different reasons.

Stevens famously stepped aside to allow Thorpe to swim the 400m at the 2004 Athens Olympics following the five-time Olympic champion's famous false start at trials.

But in a remarkable turn of fortune, Stevens was handed a late berth for this year's Melbourne Commonwealth Games because of Thorpe's withdrawal due to illness.

Hackett praised Stevens, who lopped 1.33sec off his best time to nail down a world championships berth.

"He is not that far off the medal dais, if he can keep on improving that really puts him up in the world rankings," Hackett said.

The Chandler complex, built for the 1982 Commonwealth Games was showing its age early on with a leak dripping into lane four.

However Linda MacKenzie (4:06.79) briefly lifted the mood on a fairly flat opening night in the women's 400m by coming within half a second of Tracey Wickham's (4:06.28) Commonwealth record set back in 1978.

It was MacKenzie's fourth straight national title in the event but she has still to prove she can deliver on the big stage after regularly flopping at major meets.

In the women's 100m butterfly, world champion Jess Schipper (58.20s) led qualifying for Monday night's final ahead of rival Libby Lenton (59.02s).

There has been plenty of media attention on Lenton's powerful physique already this week with newspaper reports comparing her body to those of former drug cheats.

She said she was treating the accusations as a "back-handed compliment" after warming up for her gruelling five-event schedule.

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