The Phillies fell 2½ games behind the NL East-leading New York Mets. They began the day three games behind Milwaukee in the wild-card race.
"We have to keep fighting until someone tells us to go home," manager Charlie Manuel said.
At this point last season, the Phillies were seven games behind the Mets and ended up winning the division on the final day.
Ryan Howard hit his major league-leading 41st homer, but Philadelphia couldn't overcome a 9-1 deficit.
Kendrick (11-9) allowed seven runs and six hits in 1 1/3 innings.
"It's disappointing," Kendrick said. "I just have to get out of the rut. Nobody wants to go through it. It's bad timing."
"I felt like I could have kept going, but we don't want to alter my mechanics or my delivery and put more strain on the arm than necessary," Volstad said. "It was a decision we made just to be safe."
Reliever Eulogio De La Cruz allowed six runs and five hits in two-plus innings, nearly blowing the eight-run lead. Kevin Gregg (7-8) retired the side in the seventh. Matt Lindstrom, the Marlins' eighth pitcher, got the final out for his second save.
"I was worried about the pitching," Marlins manager Fredi Gonzalez said. "I couldn't tell you who was hitting for us. I was thinking about how many outs we've got left and what we've got in the bullpen."
Doug Waechter entered to face Greg Dobbs, who lined a two-run double. Pinch-hitter Matt Stairs followed with an RBI single to make it 10-8. After Chris Coste flied to right, Jimmy Rollins singled and stole second to put the tying run in scoring position.
"We fought like heck to get back, but we couldn't get the big hit to catch up," Manuel said.
The Marlins (73-72) snapped a three-game losing streak and moved back over .500.
Kendrick was skipped in the rotation his last start, allowing ace Cole Hamels to pitch against the Mets on Sunday night. Hamels struggled and the Phillies lost 6-3. Kendrick is likely headed for mop-up duty the rest of the season. He's 1-4 with an 11.35 ERA in his last six starts since beating Florida on Aug. 6.
"We only have so many options," Manuel said.
Jacobs connected off J.A. Happ in the fourth to make it 9-1. Jacobs' 32nd homer landed in the Phillies' bullpen in right-center.
Howard hit a two-run drive off De La Cruz in the fourth. Burrell followed with a standup triple, a rarity for the slow-footed slugger, and he scored on Victorino's groundout.
Ross hit a solo shot off Happ leading off the fifth, extending the lead to 10-4.
Werth had two of Philadelphia's four steals. He's 16-for-17 this season. The Phillies are 121-for-143, the best percentage (84.6) in the majors. ... Since Happ was used, 45-year-old Jamie Moyer likely will start on three days' rest Thursday night against Milwaukee. Happ was being considered for that start. ... Jacobs is one homer shy of tying Carlos Delgado for the club record by a left-handed hitter. Delgado hit 33 in 2005.