Trainers Debbie Cannan and Pat Ryan will each take two of the fastest qualifiers to the semi-finals of the Breeders Classic in Launceston on Monday night.
Six greyhounds went under the 30-second mark in the 16 heats conducted on March 13.
The Cannan-trained Kintyre was the quickest in 29.85 while kennel-mate Siberia won in 29.99.
Ryan's fastest winner was Ava Wine in 29.86 with kennel-mate Handsome Prince recording 29.89.
Ted Medhurst's Jenifer Alice (29.95) and Butch Deverell's Inner Circle (29.98) were the others to break 30 seconds.
Kintyre and Handsome Prince clash in the first semi while Jenifer Alice and Inner Circle meet in the fourth.
Last week's Launceston meeting was highlighted by Freya The Slayer's big win in the Grade 4/5 at her first run over 600m.
The Ted Medhurst-trained bitch was wide for much of the race before railing inside Wynburn Gold in the closing stages to snatch victory by 3/4 length.
She will be out to repeat the performance in this week's third race where she has drawn the red and is odds-on in the Greyhound Recorder's predicted market.
Blake Pursell's Sprint Gordon out-gunned a good field to win the Invitation in 29.60.
It was the quickest time he has recorded in six starts over the Launceston 515m course.
Left in his wake were quality rivals Outlaw Teddy, Mr Camacho, Hello Rhonda, Connected and Buckle Up Azona.
Sprint Gordon has now won eight of his past nine starts and 10 of 20 overall.
He will try to build on that imposing record in the Invitation in Hobart on Thursday night.