The Bruins (48-14), the No. 2 national seed, sent 10 batters to the plate in the first against Tyler Johnson (12-2), who allowed a season-high seven runs in 2 1-3 innings. Jeff Gelalich's bases-loaded single opened the scoring, and Kevin Williams' two-run double off Jasvir Rakkar in the third made it 7-1.
Pat Cantwell homered for Stony Brook (52-14).
Plutko (12-3) allowed five hits and struck out seven in seven innings. He has given up three runs and 14 hits in 23 postseason innings.
Stony Brook (52-14) has staved off elimination five times in the NCAA tournament and will have to again Sunday.
ARIZONA 4, FLORIDA STATE 3, 12 innings
Johnny Field's RBI double in the top of the 12th inning lifted Arizona to a victory over Florida State.
Joey Rickard had doubled into the left-center gap for the Wildcats' first hit off Florida State closer Robert Benincasa (4-2), who came on in the ninth. Field followed with his two-base hit to right, driving in Rickard.
The Seminoles scored two unearned runs off Arizona starter Kurt Heyer to tie it 3-3 in the sixth but had only three batters reach base the rest of the way.
Wildcats freshman closer Mathew Troupe (5-1) worked the last 2 2-3 innings for the win, striking out Devon Travis to end the game with a runner on third.
Arizona (44-17) plays UCLA on Sunday night in a meeting of Pac-12 co-champions. The Seminoles (48-16) meet Stony Brook in an elimination game Sunday.