Padres 6, Royals 5 (12): Will Venable lined a single to knock in two runs in the bottom of the 12th inning as San Diego rallied to beat Kansas City in the opener of a three-game series.Chris Denorfia singled and Yonder Alonso doubled before Venable's shot to right field off Tim Collins (0-2) made Tim Stauffer (1-0) the winner after he allowed a run in the top of the frame. Yasmani Grandal belted a three-run homer, Jedd Gyorko tied it with a solo blast in the ninth and Seth Smith had two hits for the Padres.Eric Hosmer recorded a solo homer and two singles and Lorenzo Cain had four of a season-high 16 hits for the Royals, who have lost five straight games. Salvador Perez doubled for his third hit with one out in the 12th and came home on Mike Moustakas' line-drive single with two outs to give Kansas City a 5-4 lead.Danny Valencia's RBI single opened the scoring in the second inning and the Royals pushed their advantage to 3-0 on Hsomer's two-run single in the fifth. The Padres ended Kansas City starter Yordano Ventura's 18-inning scoreless streak in the sixth when Grandal hammered a 1-2 pitch into the right-field seats to tie the game at 3-3.Hosmer responded in the seventh, taking a 3-2 pitch from Nick Vincent over the right-field wall for his first of the season. That lasted until one out in the ninth when Gyorko hit the second pitch he saw into the left-field seats off closer Greg Holland, who blew his first save in eight chances.GAME NOTEBOOK: Kansas City has lost all seven interleague games at San Diego in its history. … The Padres recalled INF-OF Kyle Blanks from Triple-A El Paso and he struck out twice in two plate appearances Monday. San Diego also designated INF-OF Xavier Nady for assignment. … Ventura, who had a single for his first major-league hit, allowed three runs on five hits and struck out a career-high 10 in six innings while San Diego starter Eric Stults yielded three runs and 11 hits with two strikeouts over 4 2/3 frames.