Sally McLellan is shaping as the outright 100m hurdles gold medal favourite at next month's world championships after smashing her own national record with another stunning victory in Monaco.

McLellan clocked 12.50 seconds to beat a world-class field at the super grand prix meet, slashing three hundredths of a second off her previous best set at the same venue last year.

The Queenslander bolted out of the blocks and never looked like being beaten, with Canada's Olympic bronze medallist Priscilla Lopes-Schliep (12.54) and American Lolo Jones (12.61) claiming the minor placings.

Olympic champion Dawn Harper was sixth, while reigning world champ and fellow American Michelle Perry was a late withdrawal.

Only Jones has now run faster than McLellan in 2009 and she has failed to earn a place on the star-studded US team for the world titles in Berlin.

"I knew I had the Australian record in me," said the 22-year-old McLellan.

"(Breaking the record) shows that I'm on track. Everything is really going to plan.

"It has built my confidence so much.

"I'm excited but I've still got one more race (in Stockholm on Saturday morning AEST) to go.

"I wanted to take advantage of the race I was in with those girls, and I came out on top which was a big confidence booster.

"I got my good start like I always do and continued to run faster during the race.

"From hurdle three onwards I just felt so strong. I don't think I've ever felt that strong in a race before."

McLellan has now clocked her fastest two times in Monaco, with last year's run coming just a few weeks before her spectacular silver medal performance at the Beijing Olympics.

Her buildup to Berlin has been even more impressive, with five victories in six meets in Europe.

The other standout performance in Monaco came from American Lashinda Demus, who moved to fourth on the alltime list with a stunning time of 52.63 in the 400m hurdles.

With Jana Pittman-Rawlinson unable to defend her world title in Berlin due to a back injury, the gold medal is likely to be fought out between Demus and Olympic champ Melaine Walker from Jamaica.

Australian long jump stars Mitchell Watt and Fabrice Lapierre failed to make much of an impression in Monaco. Watt was sixth behind winner Godfrey Mokoena of South Africa with a best effort of 7.94m, while Lapierre eran through the board on his first and only attempt. Kimberly Mickle was seventh in the javelin with a best throw of 58.77m.

John Salvado
AAP