Ryan McMahon smacked a two-run home run in the top of the 12th inning as the visiting Colorado Rockies outlasted the Oakland Athletics 4-3 to snap a four-game losing streak Wednesday night.

After Oakland's Zack Gelof had extended the contest with a two-out RBI single in the last of the ninth, neither team scored until McMahon connected off Kyle Muller (0-1) for his ninth homer, scoring ghost runner Jake Cave ahead of him.

Nick Mears (1-3), who struck out the side with the potential tying run at second base in the 11th, saw the A's draw within 4-3 on a double play grounder by Gelof in the last of the 12th, then walked Tyler Nevin with two outs.

That brought on reliever Matt Koch, who was promoted from the minors on Sunday and made his season debut on Wednesday. He walked Kyle McCann on four pitches to move the potential tying run into scoring position before retiring Max Schuemann on a fly to right to lock down his first save of the year.

The outcome required extra innings after the A's, held to one run and five hits over a career-best-tying eight innings by Rockies starter Austin Gomber, drew even in the last of the ninth on Gelof's hit off Colorado closer Jalen Beeks.

Gomber, who twice went eight innings for the Rockies during the 2021 season, recorded 24 outs for a third time, allowing just one run on a homer by JJ Bleday in the fourth.

Staked to a 2-0 lead before throwing his first pitch on a home run by Elias Diaz, Gomber retired the first 10 men he faced before Bleday's sixth homer of the season.

The impressive outing, which included no walks and six strikeouts, continued a near-perfect May for Gomber, who shut out the San Diego Padres over six innings in his previous outing after having allowed just one earned run in 12 2/3 innings in his first two starts of the month.

Diaz gave Gomber a 2-0 lead 16 pitches into the game, bombing his fourth home run of the season to center field. The blow also scored Charlie Blackmon, who had led off with a single, after which Oakland starter Mitch Spence struck out two before Diaz came to the plate.

Spence kept the deficit at two runs through three innings, leaving after having allowed five hits and three walks. He struck out four.

Diaz collected three hits for the second straight night for the Rockies, while McMahon, Brendan Rodgers and Hunter Goodman had two apiece.

Gelof and Rooker had two hits apiece for the A's, who were outhit 12-8.