Gwynn's two-out RBI triple in the ninth inning preceded an RBI single to left by Vinny Rottino in the 11th inning off relief pitcher Joe Thatcher to assure the Brewers of their first winning season in 15 years.
Those two hits also, temporarily at least, made a mess of the Padres' postseason plans, as a San Diego victory Saturday would have assured it of nothing less than the Wild Card. Instead, the loss means the D-backs have earned the NL West.
The Padres (89-72) need a victory against the Brewers on Sunday to avoid a Wild Card tiebreaker game that will played Monday, as well as the possible inclusion into what essentially would be a four-team round-robin tournament Tuesday.
Win and the Wild Card is theirs, plain and simple. Lose and things get very complicated.
"It's extremely frustrating," said Hoffman, who allowed Gwynn's game-tying hit after he yielded a double to Corey Hart earlier in the ninth inning. "When you are on the brink of something like that, you try and execute to get that last out ... that's how elusive it can be sometimes."
Hoffman has blown leads before -- four this season before Saturday. But those held nowhere near the importance of the one that got away against the Brewers, although things didn't appear to be headed in that direction.
On the strength of Chris Young's pitching, continued strong work from the bullpen and a big day at the plate from Adrian Gonzalez (home run, three RBIs), the Padres carried a 3-2 lead into the ninth, with the Major League's career saves leader ready to get the last three outs of the game.
Hoffman made quick work of Prince Fielder, making the big first baseman look very bad chasing a changeup down in the strike zone. Even after Hoffman allowed the double into the left-field corner by Hart, he wasn't necessarily in bad shape, especially after striking out Laynce Nix for the second out.
Gwynn, who entered the game as a pinch-hitter, took the first pitch from Hoffman for a ball. He then swung through a changeup before taking a ball in the dirt. Hoffman went back to the changeup -- one of eight consecutive changeups he would throw in the ninth inning -- and Gwynn swung through that one as well.
Hoffman went back to his pitch and even threw it in a place (low and in) where he didn't think that Gwynn could reach it. The youngster did, though, lining the ball into the right-field corner, giving Hart plenty of time to score.
"He did a great job of hitting," Hoffman said. "The pitch before, he swung right through that pitch. The ball was down. You've got to give him credit. He saw a lot of changeups in that at-bat and made the adjustment."
In the 11th inning, the Brewers (82-79) got a leadoff double from Ryan Braun, and the Padres elected to walk Fielder intentionally. Braun went to third base on Hart's fly ball. Rottino then jumped on a first-pitch cut fastball -- he said afterwards that he knew Thatcher, a former teammate, would throw that pitch -- to win it.
"We'll be all right; we've had tough losses before," Padres manager Bud Black insisted. "We have done it all year. The guys are fine. That's why we play."
Nearly lost in the Brewers' late-inning comeback was a strong performance by Young, who allowed two runs on two hits over six innings. He did walk four, but he had seven strikeouts.
"I thought Chris' stuff was good -- two hits through six innings. His command was a little bit spotty at times," Black said. "But when push came to shove, he made some pitches. I think he is inching closer and closer to regaining his form that we are all used to seeing Chris have."
The Padres can only hope that their Sunday starter, right-hander Brett Tomko, can come close to replicating Young's effort. Tomko, cast adrift by the Dodgers late last month, is starting because Jake Peavy would start a must-win game Monday, though the team has won all three games Tomko has started.
"It comes down to tomorrow. ... It's my last start going out there," said Tomko, who isn't eligible for the playoff roster. "I came here trying to help the team win, and I was hoping I could win a couple games and make a difference. I didn't think it would come down to the last game. It's a great situation to be in."
But then so was the situation that Hoffman stepped into Saturday. He was one out away from career save No. 525 and No. 43 for the season, but, more importantly to him, much more so than any shining number, one out away from the postseason.
"We're working toward winning the division, a Wild Card berth," Hoffman said, his right arm wrapped in ice. "And my job is to get outs."