Rookie Buster Posey hits two homers including his first career grand slam in San Francisco’ 15 – 2 romp over Milwaukee. The Giants hit three homers to go up 4 – 0 in the 1st inning and never look back. Tim Lincecumstrikes out 10 over 7 innings for the win.

With the score tied at seven in the bottom of the ninth at Coors Field, Rockies catcher Chris Iannetta makes Evan MacLane’s major league debut memorable when he leads off the inning with a game-ending home run off the 27 year-old rookie. The Cardinals’ southpaw is the first hurler to surrender a game-winning homer to the first major league batter he faces since San Diego’s right-hander J.J. Trujillo accomplished the dubious deed in his major league debut by allowing Baltimore’s Tony Batista to end a game with a round-tripper in 2002.

Adam Dunn becomes the second Washington Nationals’ player to hit three home runs in a game, and the first major leaguer to accomplish the feat at the three year-old Nationals Park. The first baseman’s offensive output, which matches Alfonso Soriano’s performance in 2006, helps the home team edge San Diego, 7-6, on a very warm night in the nation’s capital.

Adam Dunn hits three home runs in the Nationals’ 7 – 6 win over San Diego, driving in 5 runs. He is the second player to accomplish the feat since the team moved to Washington, DC, after Alfonso Soriano in 2006. In the 9th, pinch hitter Matt Stairs of the Padres hits a solo homer off Matt Capps, the 20th of his career, tying the record held by Cliff Johnson. However, Capps holds on for his 23rd save. San Diego’s Adrian Gonzalez and Washington’s Ian Desmond also go deep on a night when the long ball is king.

Alex Rodriguez hits the 21st grand slam of his career and adds a solo homer to bring his career total to 597 long balls. The Yankees defeat the Athletics, 6 – 1. CC Sabathia wins his 7th consecutive start to improve to 11-3 on the year. A-Rod’s slam ties him with Manny Ramirez for second on the all-time list, two behind Yankee legend Lou Gehrig.

The Rockies explode for 9 runs in the bottom of the 9th to beat the stunned Cardinals, 12 – 9. They enter the inning down 9 – 3, but score and score some more, capping the rally with Seth Smith’s three-run walk-off home run off closer Ryan Franklin. Chris Iannetta also hits a three-run homer off Franklin, who gives up 6 runs in a third of an inning. Manuel Corpas (3-5) is the beneficiary of the outburst. It is only the third time in major league history a team has scored nine or more runs in the bottom of the 9th to win and the first time since 1901.

Joey Votto, in competition for the last spot on the National League All-Star team, hits two solo home runs in the Reds’ 8 – 6 win over the Mets. The game features the ejection of Mets manager Jerry Manuel, who complains over a ruling that Scott Rolen is hit by a Mike Pelfrey pitch with the bases loaded in the 5th, scoring the go-ahead run. Manuel argues that the ball tipped Rolen’s bat, but is tossed when he tries to press his case. Drew Stubbs and Corky Miller follow with two-run hits each, then pitcher Travis Wood hits a triple to make it 7 – 1. The Mets counter with 5 runs of their own in the bottom of the frame, but never manage to catch up.

Drew Stubbs hits 3 of the Reds’ 7 home runs in a wind-aided 14 – 3 demolition of the Cubs at Wrigley Field. Four of Cincinnati’s long balls come after two outs in the eight-run 7th inning. Rookie Tyler Colvin bangs two homers of his own in a losing cause. For the Reds, 1B Joey Votto is ejected in the 1st inning for arguing balls and strikes, but his replacement, Paul Janish, goes 4 for 4 with one of the homers.