Natalie Lathrop banked in a right-wing 3-pointer at the final buzzer to give fifth-seeded Marshwood a 46-43 win over fourth-seeded Greely in a Class B South girls basketball quarterfinal Friday at the Portland Expo.

Lathrop, who led all scorers with 17 points, had to hurry her shot after receiving a knee-high pass from Maddison Poitras, who gathered a loose ball with time running out.

Marshwood (14-5), which played exclusively Class A schools during the regular season, advances to a semifinal at 6:45 p.m. Wednesday at the Expo against No. 1 Gray-New Gloucester or No. 8 Freeport.

Marshwood trailed 9-2 after one quarter but used a 20-7 second-quarter advantage to take a 22-16 halftime lead.

Greely (13-6) had the edge in the third quarter behind the shooting of Hannah Hussey and Avery Bush, who combined for 14 of the Rangers’ 19 points, and tied the game at 35-35.

Marshwood forged ahead again in the fourth on 3-pointers by Jolie Folger (eight points) and Isabelle Tice (14 points) before Greely tied it on a 3-pointer from Bush.

Bush and Hussey each finished with 11 points.

YORK 58, POLAND 51: Nya Avery scored 16 points, Piper Catanese added 14, and third-seeded York survived Poland’s fourth-quarter comeback in a Class B South quarterfinal, holding on for a win at the Portland Expo.

York (13-6) led 43-30 after three quarters, but the sixth-seeded Knights (12-7) tied the game on a Phoebe Paradis layup with 40 seconds left. York went back ahead on a pair of Maddie Fitzgerald free throws with 29 seconds to go, then held Poland scoreless on the next possession before sealing the win at the free-throw line.

Sophie Coite and Lucy-Mae Taylor added 10 points apiece for the Wildcats, who next play Wednesday against second-seeded Oceanside.

Paradis had 10 points and Charlotte Grenier scored nine for Poland.

OCEANSIDE 72, LAKE REGION 37: Second-seeded Oceanside used a 46-17 advantage of the middle two quarters to pull away from No. 10 Lake Region in a Class B South quarterfinal at the Portland Expo.

Renee Ripley and Addie Poland each hit a pair of 3-pointers during a 25-8 surge in the third quarter. Ripley finished with 21 points and Poland, a slender senior guard, scored 17, to go with a team-high eight rebounds.

Freshman Olivia Breen led Oceanside in scoring with 22 points, 11 in the fourth quarter.

Oceanside (18-1) will play No. 3 York (13-6) at 5 p.m. Wednesday at the Expo

Lake Region (8-12) held an early behind the play of Helena Sheldrick (12 points) until Abby Stackpole (12 points) hit a 3-pointer for the Mariners. At the half, Oceanside led 29-16.

Oceanside played nearly the entire game without junior guard Grace Mackie, a starter who injured her left arm on a drive to the basket.

GRAY-NEW GLOUCESTER 44, FREEPORT 28: Top-seeded Gray-New Gloucester (18-1) controlled things with its defense and beat No. 8 Freeport (9-11) in a Class B South quarterfinal at the Portland Expo.

Standout freshman Bryn Gilmore led all scorers with 15 points and Abbey Steele had 13, with two 3-pointers in the second quarter as the Patriots built a 29-13 halftime lead.

Gray-New Gloucester advances to a regional semifinal at 6:45 p.m. Wednesday against No. 5 Marshwood (14-5).

Freeport’s Mari Ambila scored eight of her team-high 10 points in the second half.