The rest of his day, however, wasn't quite so memorable.
Kemp failed to catch Daniel Descalso's fly ball near the wall in right in the third inning with two outs, leading to two runs as he was charged with an error. Kemp appeared to battle the sun as he drifted back, losing the ball at the last moment.
"You always have that [sun] in right field, there's tough sun there," said San Diego starting pitcher Ian Kennedy, who took the loss. "Day games are tough for the outfielders."
Instead of the inning being over and the score remaining tied, Kemp's error allowed the Rockies to take a 5-2 lead.
"He doesn't usually drop that ball. That's a tougher play than fans can see. Things went against him today after his two-run home run," said Padres interim manager Pat Murphy. "We've got to pick him up. We've got to pick up the guy who has been carrying us a lot."
Later, as the Padres tried to cut into the Rockies lead, Kemp grounded into double plays in the third and fifth innings. Kemp also struck out in the seventh inning as the Padres fell in the first game of a four-game series.
Kemp went 1-for-4 with the lone hit his 19th home run of the season. He's hitting .303 with 11 home runs and 44 RBIs in 46 games in the second half.
"I know that Kemp has led us to many victories. He has been unbelievable," Murphy said.
Eleven of Kemp's 19 home runs have come at spacious Petco Park and his two-run shot to left field in the first inning off Rockies' pitcher Kyle Kendrick certainly came at a good time, as Colorado scored twice in the first inning.
In the bottom of the inning, Yangervis Solarte doubled and then trotted home as Kemp jumped on a first-pitch sinker from Kendrick, lining it over the left field wall. Statcast™ tracked the ball at 107 mph off the bat.
"It was huge. It kind of wipes the slate clean," Kennedy said of the home run. "It's kind of like a do-over."