Pietersen struck a quickfire 66 on Thursday during the Stars??? opening-game defeat to Adelaide Strikers, but was caught behind third ball at Melbourne Cricket Ground on Saturday as his side slipped to a second consecutive reverse.
Hobart, last term???s runners-up, posted 190-5 from their 20 overs with Jonathan Wells plundering 68 off 44 balls and Ben Dunk (43 from 42), while Darren Sammy (38 from 12) also contributed.
Stars captain Cameron White struck a 48-delivery 62 in reply but none of his team-mates scored above 20 as the Hurricanes restricted their opponents to a total of 138-9.
Hobart did not make a great start to their innings, with Alex Hales ??? backed by Sir Ian Botham to open for England in the World Cup after Alastair Cook was dropped – departing for a second-ball duck and Tim Paine (19) and George Bailey (2) back in the shed with only 31 on the board.
But Dunk ??? the top run-scorer in Big Bash 2013-14 with 395 from his 10 matches ??? and Wells put on 90 for the fourth wicket in 10 overs, before Dunk was pouched by Glenn Maxwell off James Faulkner???s bowling.
Maxwell caught out Wells, too, to leave the Hurricanes 143-5 in the 18th over, but Sammy???s stunning innings ??? he cracked four fours and three sixes to earn a strike rate of 316.67 ??? ensured the Tasmania-based side bagged 47 runs from the final 12 balls.
Stars scored briskly early on but when Luke Wright exited for 13 in the fourth over ??? edging economical seamer Joe Mennie behind to Dunk ??? they capitulated, with Pietersen next to go after becoming one of Ben Hilfenhaus??? four victims.
Maxwell (12), David Hussey (11) and Faulkner (20) were the only players besides White and Wright to make double figures, with regular breakthroughs allowing Hurricanes to strangle their opponents.
Mennie took three wickets in his four overs at a cost of just 20 runs, while Hilfenhaus ??? who will play for Nottinghamshire in the latter part of the 2015 county cricket season ??? shipped only 27 runs.
White???s dismissal, with the score on 107 in the 15th over, extinguished any chances of some late drama, with Jackson Bird the last man out, clipping a Mennie delivery into Bailey???s grateful hands.