CLEMSON - The stands had mostly emptied of fans, and who could blame them?

Down seven runs at stretch time, down five going to the ninth, down four with one out left and down three while down to their last strike on multiple pitches. Down, down, down, like the perpetual direction of Clemson's baseball season.

Oh, and Clemson was 0-20 when trailing after eight innings. Emphasis on "was."

Leave it to a couple guys hitting below the Mendoza line to heave a life saver. Freshman Andrew Cox drew a bases-loaded walk, then senior Jon McGibbon rapped a bases-clearing double to tie Boston College at 9 apiece.

That unlikely sequence completed a comeback that followed about an hour later with Jay Baum's game-winning double to cap Clemson's shocking 10-9 victory in 13 innings Saturday afternoon at Doug Kingsmore Stadium.

"Huge win, feels great, coming back from that huge deficit," Baum said. "It's a big momentum swing for us."

Barely a thousand remained of the 3,961 fans announced in attendance, as the afternoon turned chilly and overcast - a metaphor, if you will, for the Tigers' prospects at making the NCAA tournament for the 27th time in 28 years.

So the ones who stayed, who didn't flee when the scoreboard read "Boston College 9, Clemson 2" while "Take Me Out To The Ballgame" blared, were rewarded, dancing in the aisles along with about 50 players and coaches in uniform who leaped out of the dugout to celebrate with Cox at home plate.

Meanwhile, McGibbon stood on second base flexing, and manager Jack Leggett stepped out of the third-base coaching box to pump his fist at the senior.

"It showed the character of this team," Leggett said. "We're never going to give up."

They didn't, not when Boston College failed to turn a double play on Steve Wilkerson's grounder that would have ended the affair and sent Clemson to its fifth ACC series loss in six sets. Garrett Boulware singled and Baum walked to load the bases down 9-5, but two struggling batters were due up.

Cox was a .135 hitter entering Saturday. Leggett contemplated using a pinch-hitter, then backed off, and Cox trotted to first on five pitches.

"I was thinking about it at that time," Leggett said. "Just had a good feeling about it. Worked a walk. Glad I left him in the game."

McGibbon was a .188 hitter entering Saturday. Just six extra-base hits in 81 plate appearances. He knocked out No. 7 with the eighth pitch of his at-bat, and the fifth with a two-strike count.

"It's just a matter of staying calm, keeping your nerves in check," McGibbon said. "I was able to battle and finally got a good pitch to hit."

Mike Dunster grounded out, ensuring extra innings, but Baum was the hero when he went the opposite field on an 0-2 fastball with two out in the 13th.

Starting from first base, Boulware carried his 220 pounds as fast as he could, consummating with a barrel roll at home plate.

"Felt like there was a freaking fridge on my back going around second base," Boulware said.

When BC catcher Stephen Sauter couldn't haul in the throw from right field, Boulware was ruled safe and the Tigers dogpiled behind the plate, 4 hours and 48 minutes after first pitch.

"It's all about finding the right spark at the right time," McGibbon said. "This was a big game for us, a really big game. We fought with our backs against the wall and got the job done."

Tyler Slaton socked his third homer of the season to lead off the ninth-inning miracle.

The Tigers (34-22, 15-14 ACC), avoiding their first sub-.500 ACC campaign since 2008, grabbed the fifth seed in next weekend's ACC tournament. The official bracket will be released soon.

Reliever Matt Campbell (4-0), the sixth of six Clemson pitchers Saturday, earned the victory with five sterling scoreless innings, allowing one hit and three walks against five strikeouts. Starter Jake Long lasted just one frame, getting hit hard in the first inning and giving BC a 3-0 lead.

Eagles starter Jeff Burke was strong for six innings, but the Tigers saved 14 of their 16 hits for the sixth inning onward. John Gorman (3-8) was charged with defeat.