BOSTON -- It looked as if Mauro Gomez' night was going to be the shining moment on Saturday.
Then the Red Sox' bullpen took over for Aaron Cook in the seventh inning, where Andrew Miller and Mark Melancon allowed six runs to blow a 9-3 lead.
The result was a 10-9 Kansas City win in 12 innings, thanks to a Tony Abreu two-out RBI single off Junichi Tazawa in the top of the 12th.
Before all of that, Gomez -- taking over for the now officially-traded Adrian Gonzalez -- was 4-for-4 with three RBI and a run scored, which included a solo home run in his first at-bat in the bottom of the second inning.
Mike Aviles followed up Gomez' solo shot with a three-run jack of his own, putting the Red Sox up 4-3.
In the bottom of the third, Gomez stepped up to the plate with bases loaded and no outs, and hit a slow dribbler down the third-base line. Royals pitcher Jeremy Guthrie charged it and his throw home was wild, scoring two runs and giving Boston a 6-3 lead.
Jarrod Saltalamacchia made it 7-3 in the next at-bat with a sacrifice fly to deep center field that scored Cody Ross.
Ross and Gomez put the Red Sox up 9-3 in the bottom of the fourth inning, after both ripping 2-out RBI singles to left field.
After the Royals tied the game at 9-9 with a six-run seventh, the Red Sox had several chances with runners in scoring position in both the eighth and the 10th inning. But the Royals were the next team to drive in a run, as Tony Abreu made Junichi Tazawa pay for a two-out walk in the 12th inning, by poking a two-out RBI single the other way to left field.
Jeff Francoeur was the player who walked with two outs, and after advancing to third on an Eric Hosmer single, he scored on Abreu's hit, which ended up being the game-winner.