Jershika Maple won the Instant Save on Tuesday to earn the fifth and final spot in the season 21 finale of The Voice.The 24-year-old singer from Killeen, Texas, beat out the father-son duo of Jim and Sasha Allen, Joshua Vacanti and Lana Scott as the bottom four acts performed hand-picked songs during the Instant Save.Jershika was cheered on by her coach John Legend, 42, after she became his lone contestant in the finals.