On Sunday the Tigers were leading 5-0, but poor relief pitching and an error by shortstop Damon Haecker contributed to a big inning for the home team to change the momentum.
The loss dropped Auburn's record to 27-25 and 10-17 in league play, damaging the team's chances of earning a spot in the SEC Tournament.
"We know we really let one get away," said Auburn's first-year head coach, Sunny Golloway. "We needed the tie-breaker over this bunch. Our guys knew that. We had it in hand 5-0 and we just didn't finish."
Kentucky improved its record to 12-15 in the SEC and 30-20 overall.
Auburn starting pitcher Keegan Thompson allowed just three hits before being pulled in the sixth inning after hitting a batter and giving up a double to put two runners on base.
"The turning point in the game was when they hit Keegan in the ankle with a line drive," Golloway said of an infield hit that happened in the fifth inning.
"He wanted to go one more inning, but he just couldn't," Golloway said. "It was a really gutsy effort by him because he was in total command with a 5-0 lead. Then two guys got on and we go to our bullpen.
"I think that was the turning point right there," Golloway added. "We just explained there is a guy at second and a guy at third and even if they score it is 5-2 and we are okay--get the hitter. Well, we hit the hitter and walked the hitter and they ended up scoring four runs."
Reliever Jay Wade hit the first batter he faced then walked in UK's first run of the game.
Golloway pulled Wade in favor of Trey Cochran-Gill, who forced what could have been a double-play ground ball to Haecker, but the shortstop's error cut the lead to 5-2.
On another ground ball to Haecker he turned a double play as a run scored to make the count 5-3. UK added a fourth run in the inning on a double to left field by Austin Cousino.
In the seventh inning the Wildcats loaded the bases with nobody out on a walk by Cochran-Gill, a hit batter and a bunt to third base mishandled by Connor Short that was generously ruled a hit.
Ryan Tella then was called in from center field to pitch for just the second time as a collegian. The senior lefty struck out UK's sixth, seventh and eight batters to get out of a major jam.
Auburn wasn't able to take advantage of the momentum of Tella's impressive effort as the Wildcats tied the contest with a solo homer by Austin Cousino in the eighth inning.
In the ninth inning the Tigers had a chance to regain the lead when Short singled with one out and moved to third base on a walk to Grier and a bunt single to third base by Haecker.
Blake Austin took a called third strike on a 3-2 pitch for out two and Tomscha ended the threat on a ground out.
"We took a called third strike again," Golloway said. "We have to move the barrel (of the bat). It's just baseball, it really is. It's not good baseball. We are going to regroup. It is not always going to be that way."
Kentucky won the game and the series in the 10th inning as Ka'ai Tom guided a two-out single between the second baseman and first baseman to give the Wildcats a 6-5 victory.
Tella, who pitched gave up three hits and struck out five in 3 2/3 innings, was the losing pitcher. "He did some special things for us today," Golloway said. "He really competed hard."
Like the Tigers did on Saturday, a good start at the plate took the pressure off the starting pitcher and Thompson cruised through the first half of the contest.
Auburn put up four runs on the scoreboard in the second. Tomscha opened the inning with a single and moved to third base on back-to-back walks to Tella and Jordan Ebert off of lefty Dylan Dwyer.
Thompson was credited with an infield hit and an RBI on a slow roller to second base when Ebert beat the throw to the shortstop at second base. The Tigers made it 2-0 with another ground ball, a high chopper to the shortstop who got a force out at second base.
After Short struck out the Tigers got a two-out, two RBI single from Grier on an 0-2 pitch. That scored Ebert along with Glevenyak, who had stolen second base.
The Tigers stretched the lead to 5-0 in the fourth inning with Tella opening the frame with a single and moving to second on a sacrifice bunt by Ebert. After Thompson struck out Glevenyak came through with a double over the right fielder's head to score Tella.
In the top of the sixth inning the Tigers chased relief pitcher Kyle Cody after Ebert led off with an infield single. Ebert reached second on a stolen and later moved to third base, but he was stranded there.
Spencer Jack, the sixth pitcher used by Kentucky on Sunday, picked up the victory. He allowed two hits and no runs in two innings to improve his record to 3-1.