ST. PETERSBURG, Fla.(AP) David Price doesn't have an answer why most of his success during his rookie season has come at Tropicana Field

Price allowed one run over seven innings and Carlos Pena hit a three-run homer to lead the Tampa Bay Rays to an 8-2 victory over the Kansas City Royals on Friday night.

Price (4-4) gave up five hits and improved to 4-1 at home this year.

''I feel good where ever it is,'' Price said.

The left-hander has 2.67 ERA in 33 2-3 innings at home, compared to a road ERA of 8.20 over 26 1-3 innings.

''When it comes to a young guy, some guys it's just a comfort level at home,'' Rays manager Joe Maddon said. ''We are so young among our pitchers that you're going to run into that once in a while. If it is some kind of a concern for David right now, he's going to grow out of it rather quicky.''

Pena's homer was his 26th this season, but just the third in July.

Alberto Callaspo extended his hitting streak to 13 games for Kansas City, which has lost 14 of 17. The Royals are 0-7 against Tampa Bay this season.

Pena put the Rays up 3-0 on an opposite-field shot off the left-field pole in the first.

''That's a first,'' Pena said. ''I don't remember (hitting the left-field pole) even in little league. Going the other way with strength and power is always a good sign, I think, for any hitter.''

Pena's two-out homer came off Sidney Ponson (1-7), who allowed seven runs and eight hits in 4 1-3 innings.

''I put us in a hole right away,'' Ponson said. ''I didn't pitch well.''

Callaspo singled during the second and later scored on Alex Gordon 's grounder to get the Royals within 3-1.

Jason Bartlett made it 4-1 on a fourth-inning RBI double. The Rays extended their advantage to 7-1 in the fifth when Ben Zobrist drove in a run with a triple, and Pat Burrell and Gabe Gross had RBI singles.

Tampa Bay's Dioner Navarro added a solo homer in the eighth. Brayan Pena hit a sacrifice fly in the ninth for the Royals.

Zobrist hit into a strange double play to end the third. With runners on first and third, Zobrist hit a liner that struck Ponson on the left arm and shoulder and was caught for an out by second baseman Callaspo, who then made a throw that first baseman Billy Butler couldn't handle that allowed Evan Longoria to return safely to first. Butler later threw to Gordon at third, who easily beat Carl Crawford to third base for the second out.

''I don't think I've ever seen that before,'' Royals manager Trey Hillman said.

''How strange is that?'' Maddon added.

Plate umpire Charlie Reliford left with a tear in his right calf and is expected to be out four to six weeks. The game was completed with a three-man umpiring crew.

NOTES: Maddon had no problem with the defending AL champions not making a trade before the non-waiver deadline and said the Rays have the players to compete for a playoff spot. ... Royals RHP Kyle Farnsworth , sidelined since June 25 due to a strained right groin, will be re-evaluated this weekend after experiencing renewed tightness. ... Pena is 6-for-14 with two homers against Ponson. ... Kansas City OF Jose Guillen (right knee) will have his scheduled second opinion in the next few days. Guillen is getting treatment only for the injury at the current time.