CLEVELAND -- Michael Bourn came to Cleveland as a leadoff man with speed, but it was his power that dashed the Rockies' hopes of avoiding a sweep on Sunday.
With a man on and one out in the ninth, Bourn took a fastball from reliever Adam Ottavino and launched it into the right-field seats for his first career walk-off hit. The Indians would beat the Rockies, 6-4, thanks to Bourn's decisive blast, and with it they completed their second three-game home sweep in the past two weeks.
"They said I was flying around the bases," Bourn said. "I was just happy because [it was] not only my first career walk-off home run, but we were able to complete the sweep -- just build momentum within the team."
The walk-off came with a little bit of redemption for Bourn, as well, after his errant throw allowed two Rockies runners to advance on a Troy Tulowitzki single in the third inning. The miscue set up a game-tying RBI groundout by Justin Morneau.
After Tulowitzki singled up the middle, Michael Cuddyer caught Bourn off guard when he sprinted beyond second and headed for third. Bourn rushed a throw to third base, but it was too late. Cuddyer reached safely and Tulowitzki took second.
"I think he was a little aggravated," Indians manager Terry Francona said. "He laid back on that ball in center field a little bit and Cuddyer kind of lulled him into that extra base. When that happened, I think Bourny was on a mission to help us win that game."
While the offense landed the final blow, it was Cleveland's pitching staff that fueled much Sunday's win and the sweep.
Starter Josh Tomlin held the Rockies to two earned runs over 5 2/3 innings while tying his career-best strikeout total with eight. He left the game with a one-run cushion in the sixth inning, but got hung with a no-decision. Tomlin now has a 3.06 ERA through five starts and three straight games with at least six strikeouts.
"I thought he threw his fastball in and out," Francona said of the right-hander. "I thought he threw some really good breaking balls, especially with two strikes to get a couple of them looking. Saying that, they made him work for everything. He was up around right at 100 [pitches], but he did a great job hanging in there."
However, the bullpen was no afterthought in this one, either.
The Indians' relievers held the Rockies to one run on three hits in the final 3 1/3 innings while stranding runners in the seventh, eighth and ninth innings. Right-handed reliever Scott Atchison, normally a setup man for the Tribe, picked up the win after working a scoreless ninth and lowered his ERA to 2.49 in 22 appearances this season.
"Atch has been so reliable," Francona said. "That kind of proves it right there, because you can normally go to Cody [Allen] in that inning. But, it was the bottom of the order and Atch is especially tough on right-handers. It allowed us, where if we didn't score, then we have Cody for the middle of the order. That says a lot about Atch."
The Rockies came to Progressive Field boasting one of the best lineups in the Majors, with a .288 team batting average entering the series. On Sunday, though, their lineup managed just seven hits while striking out 12 times, giving the Indians their Majors-leading 27th game with double-digit strikeouts.
The Tribe also set a franchise record by recording at least 11 strikeouts in three straight games against the same opponent. Heading into the three-game Interleague set, Colorado boasted the fewest strikeouts among National League lineups.
"I think the first couple days are a by-product of everybody getting ahead," Tomlin said. "When I was able to get ahead, I was able to put some guys away. That's when the strikeouts are going to come, especially for me. When you get ahead of a guy and you're 0-2, 1-2, you have a few pitches to play with. Pretty aggressive team like they are, if you locate those pitches you have a pretty good chance."
The Tribe offense struck early, plating three first-inning runs off Rockies starter Jhoulys Chacin thanks in large part to a trio of walks and Michael Brantley's RBI single.
The Rockies answered by pulling even over the following two frames. In the second, they cut the lead to one on a two-run blast by Corey Dickerson, which was his second of the series. The home run scored Morneau, who had reached on an error by Mike Aviles in the previous at-bat.
"The first couple innings I fiddled with my command, other pitches," Tomlin said. "My curveball I felt good with, but other than that I was trying to figure out my fastball and cutter for those first couple innings for sure."
The back-and-forth only continued from there.
Once again proving himself reliable as a No. 3 hitter, Brantley rapped out a leadoff double and later scored on a sacrifice fly from Lonnie Chisenhall to put the Indians back on top, 4-3. Chacin would leave the game charged with four runs over his five innings of work, which included five walks to only four strikeouts.
"I thought we did a good job today early," Francona said. "It looked like Chacin in the first inning really had a tough time getting loose and kind of getting into the game."
With the sweep, the Tribe extended its home winning streak to six games and improved to an American League-best 18-11 at home. It was the team's fourth walk-off win of the season.
For Bourn, he savored being the reason behind the pile.
"My adrenaline was going," Bourn said with a smile. "It was just a good moment, a moment that you won't forget in your career, even when you get through. I'll cherish that."
Alec Shirkey is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.