PITTSBURGH -- By modern definition, Pittsburgh Pirates right-hander Ivan Nova is an iron man, a bulldog on the mound who piles up innings and allows the less durable arms in the bullpen to get their proper rest.

In each of his first 15 starts, the 30-year-old Dominican pitched at least six innings, which not only is impressive during these times but also is a feat no Pirates pitcher had achieved since 1981.

In start No. 16 on Wednesday night, however, Nova lacked his usual sharpness, threw a lot of pitches (89) and came out of the game after five innings.

Still, he was good enough when he had to be as the Pirates beat the Tampa Bay Rays 6-2 at PNC Park.

Nova (8-5) gave up seven hits and walked two -- a wild streak by his standards -- but allowed only runs in the first and third innings.

Nova and four relievers held the Rays scoreless in the last six innings.

"Obviously, not the best one today," Nova said of his start. "I found a way to rally to five innings and gave my team a chance to win the game. It was a battle. These days, you feel like you have it, but you don't. I didn't make a lot of (good) pitches, but I made the right one when I needed to."

Rookie Josh Bell hit his 15th homer and Jose Osuna had two run-scoring doubles for the Pirates.

Left-hander Blake Snell (0-5) returned to the Rays after a stint in the minors and gave up four first-inning runs. He pitched five innings, yielding six runs and six hits. Snell struck out six and walked five.

Evan Longoria's RBI double gave the Rays a 1-0 lead in the first inning. Nova got the final two outs to prevent further damage.

In the third, the Rays put runners on second and third base with none out but only one run scored.

Snell, who started the season as the Rays' No. 4 starter before he was sent down to Triple-A Durham on May 14, had a rocky first inning after two quick outs, walking three and uncorking a wild pitch. Osuna's double scored one run, another scored on a wild pitch, and Elias Diaz drove in two with a single.

"Probably not the start we were hopeful of for Blake," Rays manager Kevin Cash said. "I think you saw a young pitcher that was really excited to get back to the big leagues, probably was a little over-amped. And it showed up in the first inning."

Snell retired seven straight hitters before Bell's homer leading off the fourth made it 5-2. Osuna added an RBI double in the sixth.

NOTES: Tampa Bay recalled LHP Blake Snell from Triple-A Durham, selected LHP Adam Kolarek from Durham and optioned LHP Jose Alvarado and RHP Austin Pruitt to Durham. The Rays also transferred OF Kevin Kiermaier from the 10-day to the 60-day disabled list. ... 1B Josh Bell's 15 home runs tied Hall of Famer Ralph Kiner (1946) for the most Pirates' homers by a rookie before the All-Star break. ... Rays C Wilson Ramos, a free-agent acquisition who returned Saturday from September knee surgery, made his second straight start behind home plate