The home run broke up a scoreless game that featured Romano (0-2) and Brewers right-hander Junior Guerra, who worked into the sixth inning. He did not figure in the decision but lowered his ERA to 0.82 in the early season.

Guerra and a trio of relievers combined for a three-hitter.

Lorenzo Cain led off the bottom of the sixth with a walk and went to second moments later when Romano threw wildly to first on a pickoff play.

Thames, who missed Monday's game with a groin injury, then drilled the first pitch from Romano into the seats in right field.

Guerra pitched 5 2/3 innings, allowing only one hit, striking out seven and walking three in throwing 93 pitches.

Brewers left-handed reliever Dan Jennings (2-0) picked up the win. He came on with a runner on first base and two outs in the top of the sixth inning to retire Reds second baseman Scooter Gennett, a left-handed hitter who slugged a career-high 27 homers last season, on a fly ball to center.

Romano went five innings, giving up the two runs on four hits. He walked two and struck out four.

Reds catcher Tucker Barnhart, who replaced Devin Mesoraco to start the bottom of the sixth, led off the Reds' seventh inning with a double off Jennings, one of his two doubles in the game, but reliever Jeremy Jeffress came on to strand Barnhart at third base.

Brewers reliever Josh Hader pitched two scoreless innings to get his second save of the season. He struck out three.

Relievers Amir Garrett, Dylan Floro and Cody Reed each pitched a scoreless inning for the Reds.

--Field Level Media