In the fifth, Kent put the Mets up by 6-2 with his first home run of the season, a two-run blast over the left-field wall.
Rivera also had a two-run blast in the opening-game loss.
In the top of the fifth, however, Rickey Henderson struck again with another two-run blast that increased the A's lead to 5-1.
The two-run blast gave Philadelphia a 7-6 victory.
In the top of the third, Brandon Phillips put the Reds up with a two-run blast.
Gilkey pounded a two-run blast over the center-field wall to make it 5-4.
Do I jump on Johnny when he gives up a two-run blast?
Matt Williams turned out to be the offensive hero by reaching base six times, which included a two-run blast in the eighth to close the scoring.
The two-run blast also scored Dave Magadan, who had singled to start the inning.
Olerud's two-run blast off the base of the scoreboard in right was his eighth of the season.