Asdrubal Cabrera started the inning by drawing a walk and one out later, Carlos Santana also received a free pass.
"Those two walks are what ultimately killed me," Reed said. "I know I'm going to give up hits, so the one to Gomes didn't frustrate me too bad other than there was a guy in scoring position and the game-tying run scored. Mostly I was frustrated with those two walks."
At the midway point of the season, Reed has blown three saves and has allowed eight home runs. The home run total is the most in the National League and only Ernesto Frieri and Shawn Tolleson have as many in the American League
Reed allowed six home runs all of last season.
"It could have gone a lot better," Reed said when asked to evaluate his first half. "I've also done some things that I've liked. Mechanically I changed a couple of things that feel good now, I feel comfortable. I definitely wouldn't give me a passing grade. I think I definitely think I have room for improvement."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.