Guy, a group 1 and Newcastle premiership-winning driver, defied illness to steer colt Roclea Ruler and filly La Cabeza Gem to front-running wins in their two-year-old races and spots in semi-finals at Menangle on October 10.

Sydney reinsman Robbie Morris will drive the pair in semis, where a top-five finish secures a place in the group 1 deciders.

"Mitch deserves a big rap," Guy said. "He's done everything all week, I haven't been here, and the horses are flying.

"Roclea Ruler can really run but we don't know how good he really is yet. He's getting better all the time and he's going to be a nice horse.

"This might be a little bit too quick, but Robbie Morris has jumped on both in a fortnight so we've got the best wanting to get on, so we must have some hope.

"[La Cabeza Gem] is a big chance. She was probably 70 per cent right, so if we can get her 100 per cent, she'll make the final."

Roclea Ruler clocked a career-best 1:56:0 mile to hold out Michael Dawson's race favourite Western Shilo by 1.4m, while La Cabeza Gem won by 7.5m from the Paul Fitzpatrick-trained Heaven Island in 1:57:7.

Mitch said La Cabeza Gem had been a doubtful starter before capping "by far the best night we've had".

"She tired up during the week but on Friday morning we took her for a walk and she was pretty good," Mitch said.

"She went 56.9 the last half and Dad said if something went with her, she could have gone quicker. Hopefully in the semis she will give a good show."

"[Roclea Ruler] is a pretty cool horse and as soon as he found the front, he was going to be hard to beat. He's really starting to find his feet the last month with constant racing."

In the other male heat, top Sydney trainer Craig Cross won with Pantaloon ahead of Blake Fitzpatrick's Meldrum. Fitzpatrick claimed the other fillies heat with Breivik from Roy Roots jnr-trained Our Bella Lucia.

Also on the night, Kearsley trainer Brendon Flaherty had a special win with Shining Frost, which carried his family's colours after the death of his father, Ray, last week.

Driver Tom Ison had a winning treble with Stunin Magic, Glenn Ford and Mike Orr.