MAHOPAC — MaryJane Callahan has always been a heck of a defensemen.

But midway through this season, Scarsdale coach Lauren Barton moved her up to midfield.

Riley Iasiello was completely on board.

After all, she and her fellow senior have "really good chemistry up and down the field," Iasiello explained.

And it was their chemistry in the offensive circle Sunday that lifted Scarsdale to a win in its Class A state regional final at Mahopac High School.

Callahan's goal off an Iasiello feed with 7:12 left in the first quarter held up, aided by a negated Bethlehem goal, a Bethlehem shot that hit the crossbar and a diving save by Raider keeper Gabriella Lopez off a closing Bethlehem corner with just seconds remaining in the game.

The win lifts Scarsdale to the state Class A semifinals.

Callahan took top game honors for that winning goal and her overall play, which included two fourth-quarter takeaways.

Scarsdale (14-4-1) — The Raiders had an 8-7 penalty-corner advantage. Their play off the corner improved in the second half, despite the absence of goals to show for it. Lopez didn't face half as many shots as her counterpart but that perhaps made her closing save even more special. As it was, she notched the shutout with seven stops. Kenzie Mauro, who was strong defensively throughout, stopped a Bethlehem corner shot after time expired in the third quarter as play went on, since it was a corner.

Bethlehem (12-8) — Scarsdale dominated play in the first half but the third quarter belonged to the Eagles, who were debuting at regionals. Bethlehem seemed to score off a ping-ponging, deflected ball off a corner with 7:14 in the third quarter but its celebration was short-lived as the closest ref to the play ruled the initial drive off the corner was too high, coming from outside the circle. A few minutes later, the Eagles' bad luck continued as their drive off another corner deflected into and not under the crossbar. Eagle keeper Teagan Rosencranse, a sophomore, was consistently good and sometimes outstanding. She had 15 saves, including a couple by diving.

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Eagle coach Dawn Austin was, as might have been expected, unhappy Bethlehem's apparent score was taken off the board. She said the goal should have stood because the initial shot was, in keeping with rules, no higher than the net's low, wooden liner and had been deflected up. She said no call was made on her team's crossbar shot, which she said was deflected off a higher shot.

But Austin also focused on the positive.

"We came down knowing Scarsdale is a very good team. This is our first time in history at a regional and I'm very proud. I think we played very well," she said.

Callahan said she didn't think her shot would go in. With a defender on her back, she took the pass from Iasiello and spun, releasing the shot.

She characterized the game as "stressful," since Scarsdale could never pull away.

Callahan attributed the win to her team's "strong, smart passing and give-and-go balls."

Iasiello saluted Bethlehem, saying, "Their team was pretty incredible on defense. Their block-tackle was just incredible and it took time for us to adjust."

"It's an incredible feeling —senior year after working so hard. I'm just so proud of this team," Iasiello added of the win.

Scarsdale will play in the state Class A semifinals Saturday at 10 a.m. at Long Island's Centereach High School.

Nancy Haggerty covers cross-country, track & field, field hockey, skiing, ice hockey, girls lacrosse and other sporting events for The Journal News/lohud. Follow her on Twitter at both @HaggertyNancy and at @LoHudHockey.