The Bulls, who are new to the competition, made formidable opponents due to their size and speed, and the Magpies struggled to gain the ascendancy.

The first half was an arm wrestle early, with the Bulls making early inroads and working their way up the field, but Yass managed to defend an entire set on their own tryline before rebounding to camp in the Bulls' half for the rest of the first period.

At half time, the Magpies had crossed twice for a 10-0 lead.

"Our first half was outstanding," Yass coach Josh Hardy said.

"We came out of the blocks a bit slow in the second half, but that's an area we can work on."

After another fight for momentum, the Bulls crossed twice early in the second half. With ten minutes to go, the visitors led 10-12 and looked unlikely to give up their advantage.

However, the Magpies showed why they were grand finalists in 2018, and found a way to cross for one more try with only a few minutes left on the clock.

At the buzzer, Shannon Wright slotted a penalty goal to put the icing on the cake for Yass and seal a tough 18-12 win.

"The girls really bounced back [in the second half]," Hardy said.

"We knew we had to get back into the arm wrestle, and if we got back into the arm wrestle, we could do anything."

While it is good for the Magpies to begin the season with a gritty win, Hardy said that most of the teams in the draw will be competitive in 2019.

"I think there's not gonna be an easy game throughout the season," he said.

"Pick of the draw really, we've got the [Queanbeyan] Blues next week, so it doesn't get any easier from there."

The Blues began with a similarly scrappy match, with a 12-10 win over the Valley Dragons, and will be looking to make a statement against Yass.

The Magpies will take on the Blues from 11.15am on Saturday May 11 at Seiffert Oval.