CUMBERLAND — The stride seems so fluid, the recovery so quick that Sofie Matson’s casual manner of conversation in the finish-line corral of a cross country race couldn’t possibly jibe with what she had just accomplished.

Namely, the fastest time in Maine schoolgirl history at Twin Brook Recreation Area, considered by many to be the toughest course in the state.

A junior at Falmouth High, Matson won the Class A South girls’ cross country championship Saturday afternoon in a time of 17 minutes, 51.74 seconds, breaking an eight-year-old mark established by Abbey Leonardi.

Leonardi, who went on to help the University of Oregon win an NCAA title, ran 18:05.59 in 2011 as a senior at Kennebunk High.

“I knew I wanted to go sub-18,” said Matson, whose previous best at Twin Brook was 18:41 in the Class A state meet two years ago. “I wasn’t really sure what the course record was.”

Greely won the Class B team title on its home course by 30 points over defending champ York, 62-92, with Cape Elizabeth two points further back. Senior Marin Provencher was third and freshmen Abby Hollis and Charlotte Taylor joined hands as they crossed the line together in seventh and eighth, with no one else around them.

In 2007, a similar act of camaraderie cost Massabesic the Class A state championship when meet officials disqualified two runners for holding hands at the finish. The rulebook has since been amended, and common sense prevailed Saturday, although Greely coach David Dowling experienced some anxious moments.

“As if running your guts out isn’t enough drama,” he said.

Six teams qualified for the state meet, with Freeport, Yarmouth and Poland joining the top three.

Poland was led by Olivia Ouellette’s sixth-place finish and Mia Turkington’s 12th-place showing.

Spruce Mountain’s Bailey Coates took 14th and Leavitt’s Ava Petrin came in 21st.

Olivia Reynolds, a Maine Coast Waldorf junior, won her third straight Class C South crown in a time of 20:05.80 that was a minute ahead of Kiara Audette of Traip Academy. Maine Coast easily outdistanced two-time defending champion Maranacook, 37-73, by packing five runners among the top 20.

Winthrop, Waynflete and Monmouth Academy also qualified for the state meet.

Jillian Schmelzer and Madison Forgue placed sixth and eighth, respectively, to pace the Ramblers. Sage Fortin was 16th and Maya Deming 25th.

For Monmouth, Kaitlyn Hunt was 20th, Holly Hunt 21st and Lydia Roy 26th.

St. Dom’s Sarah Brown placed seventh in the Class C race.

The second and third finishers in Class A, Gorham senior Kate Tugman and Falmouth junior Karley Piers, ran faster than either the Class B or Class C regional champions – but still trailed Matson by more than a minute. Tugman’s time was 18:55, and Piers clocked in at 19:11.

“She’s ridiculously efficient,” Falmouth Coach Danny Paul said of Matson. “No wasted motion. She doesn’t look like she’d be very strong, but she is.”

Bonny Eagle won the Class A South team title for a third straight year, as sophomores Emmaline Pendleton (fourth), Delaney Hesler (fifth) and Hannah Stevens (10th) led the way to a 59-83 victory over Falmouth. Eight of 15 teams qualified for the state meet next Saturday at Twin Brook.

“This lets us know we’re ready to run at states,” Pendleton said.

Lila Gaudrault, a Cape Elizabeth junior, successfully defended her Class B South title in 19:12.40 – 40 seconds ahead of her freshman teammate, Charlotte DeGeorge, and the rest of the field of 96.

“This is my favorite course in Maine,” Gaudrault said. “No matter how many times I run it, I never remember where all the twists and turns are. I love how unpredictable it is.”