Cubs fans already were streaming toward the exits as closer Ryan Pressly walked off the field. Of those left, a smattering sent him off with boos.

What had been a thrilling, extra-inning game had descended into a bludgeoning.

In the Cubs’ 14-5, 11-inning loss Tuesday, the Giants rallied for nine runs in the final inning, with Pressly charged with all of them. Eight were earned.

‘‘He’s a true professional guy who wants the ball to compete and win games for us, and he’s going to do that a lot this year,’’ second baseman Nico Hoerner said. ‘‘It didn’t line up for him today, but he’s going to be back in there and be great.’’

It was the largest extra-inning loss in Cubs history, according to team historian Ed Hartig. The previous record was seven runs, set on June 18, 1921, also against the Giants.

The nine runs allowed in the 11th were also a team record for runs yielded in an extra inning, eclipsing the seven runs the Cubs surrendered in that same 1921 contest.

The Cubs had fought back from an early deficit to reach that point.

For the offense, Miguel Amaya had the big swing early in the game, a two-run home run in the third. Dansby Swanson led off two innings with singles and scored both times. Justin Turner and Kyle Tucker had RBI singles in the ninth to tie the score and send the game into extra innings.

On the other side, Cubs relievers Drew Pomeranz, Brad Keller, Daniel Palencia, Chris Flexen and Porter Hodge combined to throw five scoreless innings after starter Colin Rea came out after five.

Then it all imploded in the 11th.

Pressly, who hadn’t appeared in a game since Thursday, took the mound with an automatic runner on second.

He gave up a leadoff double to Heliot Ramos and an RBI single to Patrick Bailey. Then Brett Wisely put down a bunt back to Pressly, who flipped home. But catcher Carson Kelly couldn’t quite put on the tag, losing the ball.

The next five batters all reached via a walk, a hit batsman and three singles.

With the Cubs trailing 12-5, manager Craig Counsell called in left-hander Caleb Thielbar to finish the inning. Pressly hadn’t gotten an out.

‘‘He hasn’t pitched a lot,’’ Counsell said when he was asked how Pressly had been feeling physically since having his right knee drained two weeks ago.

In Pressly’s previous 10 outings, he hadn’t allowed an earned run.

‘‘The score doesn’t make it look like a good baseball game,’’ Counsell said. ‘‘It was a good baseball game. The 11th was not a good inning for us, but it was two teams playing good. And we made a nice comeback, did some great things in the ninth inning to get it there. And then we had shots to win it.’’

In the 10th, Seiya Suzuki started as the free runner at second and Michael Busch drew a walk. Then Hoerner hit a long fly to right, with Suzuki tagging up to get to third with one out.

Pete-Crow-Armstrong, who has been on a hot streak offensively, followed with a strikeout in a tough matchup against left-hander Erik Miller amid booming ‘‘P-C-A’’ chants.

Counsell said bunting in that situation was ‘‘a thought.’’

‘‘They’re kind of all over the bunt in that situation,’’ Counsell said. ‘‘So you feel like maybe the ball in play’s got a better chance.’’

With two outs, Swanson hit a 103.3 mph lineout to third baseman Matt Chapman to end the inning.

‘‘Wouldn’t want anything else than a hard line drive right there, right?’’ Hoerner said. ‘‘So that one hurt, but we’ll get them [in the
series finale] tomorrow.’’