Baptista brace seals Roma victory
The forward scored with a tremendous free kick on 21 minutes and eight minutes after the break he slotted in a second.
Roma, last season's runners-up, had a terrible start to the campaign but have gradually been improving and are now up to eighth place.
The original game in October was abandoned after six minutes because of torrential rain. The rematch kicked off with six minutes already on the clock.
Ineffective Samp, who bought Fiorentina striker Giampaolo Pazzini earlier in the day, remain five points above the drop zone.