The five homers were a season high for the Mariners, who worked over Andrew Cashner and Petco Park in earning a split of their home-and-home, two-game series with the Padres.
Felix Hernandez (6-4) snapped a two-start losing streak, holding the Padres to one run and three hits in eight innings. He struck out six and walked three.
Franklin homered into the sandy play area beyond the fence in right-center off Cashner with two outs in the sixth inning. He connected again with two outs in the eighth, driving a pitch from Tim Stauffer deep into the seats in right.
The second baseman, a first-round draft pick in 2009, made his big league debut on Monday and got his first hit, a single, in a loss to the Padres on Wednesday night.
Morales homered to straightaway center leading off the second and Ryan hit a high, arcing ball that just went over the fence in the left-field corner leading off the third, both off Cashner. It was Morales' seventh and Ryan's second.
Chavez hit a two-run homer off the top of the new fence in right-center off Stauffer with one out in the seventh. The fence in right field was brought in 11 feet in the offseason to make the spacious park play more fairly.
Hernandez had only one bad inning, allowing two singles, a walk and Carlos Quentin's sacrifice fly in the fourth. Hernandez is 5-0 with a 1.54 ERA in six starts at Petco Park.
Cashner (4-3) allowed four runs and seven hits in six innings, struck out four and walked two.
The Padres have lost six of nine.
NOTES: The Padres recalled RHP Nick Vincent and optioned RHP Anthony Bass to Triple-A Tucson. Vincent, who's from nearby Ramona, was 4-3 with a 4.15 ERA at Tucson. He made his big league debut last year with the Padres, going 2-0 with a 1.71 ERA in 27 relief appearances. Bass had a 4.55 ERA in 18 relief appearances with the Padres. ... The Mariners open a three-game series at Minnesota on Friday, with RHP Hisashi Iwakuma (5-1, 2.35) facing RHP Mike Pelfry (3-5, 6.85). ... The Padres stay home and open a three-game series against Toronto, with RHP Jason Marquis (6-2, 3.70) opposing RHP Chad Jenkins (1-0, 3.60). Marquis has won five of his past six starts with a no-decision his last time out.