Hewitt produced a perfect front-running performance with Scarlet Babe, leading from start to finish to win the biggest race on the Dubbo Harness Racing Club calendar.

When winning her heat at Dubbo less than a week before the final, Scarlet Babe proved she had the gate-speed to get in front early and control proceedings.

When the draw came out for the final and the Bernie Hewitt-trained four-year-old landed gate two it was just what the Scarlet Babe team wanted.

Doug, driving for his father, controlled proceedings in the 2120m event and then made his move at the top of the back straight on the bell lap, kicking clear and going on to win by a convincing 5m.

"It's unreal. It's my first win in a Group race and it made it special at a country track and at a Carnival of Cups meeting at a club like Dubbo," Bathurst-based Hewitt said.

Scarlet Babe started on the second line of betting at $5 in the $30,000 feature, contested in front of a strong Carnival of Cups crowd, while Bernie sat in the gig of $2.50 favourite Royal Story.

While Scarlet Babe was always one of the leading contenders, Doug was never taking anything for granted with a horse who had proven tricky to work with in the past.

"She's a horse that's got plenty of ability but she's got a few kangaroos loose in the top paddock," Doug smiled.

"The gate-speed helps and that's been one of her main assets, especially at a track like this. You can get in front and control it a bit. Tonight she felt unreal."

After setting a quick pace up front early for much of the trip while others jostled for position behind him, Hewitt waited until late on the final lap to make the key move.

Island Banner ($10) and Gracie Tailjuice ($61) had been closest to the leader for much of the race but Hewitt knew they weren't the main concern, as the likes of Royal Story, Jeradas Delight ($7) and Bid For Red ($19) started to move wide and surge from deep in the field.

"She still had a fair bit in her but I just knew they would have been chasing and would have had to come wide to catch her," Hewitt said of the moment he kicked clear.

"On these little tracks if you can get a little gap on the turn it makes it harder for them to get to you."

The other leading contenders couldn't get close to Scarlet Babe as maintained the lead down the straight and went on to win in a mile-rate of 1:57:8.

"She was getting a bit weary at the end and her legs were starting to go a little but but she had enough to get past the post," Hewitt said.

It was a strong result for the Hewitt family, with Doug's uncle Mark Hewitt finishing second with Jeradas Delight while Bernie and Royal Story were fourth, just behind Steve Turnbull's Bid For Red.

"I was glad I was on the one in front," Doug added, still grinning.

It's been a busy time for Doug, who has juggled his commitments in harness racing with his captain-coach's role at Group 10 Rugby League side, Bathurst Panthers.

The Hewitt-led Panthers won last season's premiership and have started the 2019 campaign in fine fashion, sitting second heading into this weekend.

But despite those strong results it's been the horses which have got most of the attention lately.

"We've probably got too many in work at the moment to be honest but it keeps us on our toes," he said.

"The footy as well adds a bit extra and but the main focus has been on these horses and it's working for us at the moment."