Lovlina was defeated by Wales' Rosie Eccles via a 3-2 split decision in the women's 70kg light middleweight.
Lovlina won the opening round 4-1 but she lost steam in the last two rounds as Eccles came up with a brave show, throwing punches at the much-fancied opponent.
The boxer had on Saturday cruised into the quarter-finals by defeating New Zealand's Ariane Nicholson, 5-0 in the light middleweight 70kg category.
On the other hand, World champion Nikhat Zareen is assured of a medal in the women's 50kg light flyweight after she defeated Wales' Helen Jones 5-0 on Wednesday. The 26-year-old Nikhat was aggressive from the get-go against Jones at the National Exhibition Centre.