I don't have anything for this season, but the Toronto Maple Leafs had their lowest goal differential in a game in 2024-25 4 times, with a differential of -4 goals.

maple leafs biggest loss in a regular-season game this season

	TEAM	DIFF	DATE	TM		OPP	RESULT	G	GA	PPG	PPO	OPP PPG	OPP PPO	S	SA
1	Maple Leafs	-4	1/22/2025	TOR	vs	CBJ	L 1-5	1	5	0	3	0	0	29	19
2	Maple Leafs	-4	11/27/2024	TOR	@	FLA	L 1-5	1	5	1	3	2	5	24	24
3	Maple Leafs	-4	10/24/2024	TOR	vs	STL	L 1-5	1	5	0	4	1	2	41	27
4	Maple Leafs	-4	10/22/2024	TOR	@	CBJ	L 2-6	2	6	0	3	0	4	28	38
5	Maple Leafs	-3	3/22/2025	TOR	@	NSH	L 2-5	2	5	1	3	1	3	26	32
6	Maple Leafs	-3	3/8/2025	TOR	@	COL	L 4-7	4	7	1	1	1	3	21	34
7	Maple Leafs	-3	3/5/2025	TOR	@	VGK	L 2-5	2	5	1	3	1	3	31	25
8	Maple Leafs	-3	1/14/2025	TOR	vs	DAL	L 1-4	1	4	0	2	2	3	28	23
9	Maple Leafs	-3	1/11/2025	TOR	vs	VAN	L 0-3	0	3	0	3	0	0	20	18
10	Maple Leafs	-3	1/9/2025	TOR	@	CAR	L 3-6	3	6	1	2	0	3	33	34
11	Maple Leafs	-3	12/28/2024	TOR	vs	WSH	L 2-5	2	5	0	2	1	1	37	32
12	Maple Leafs	-3	12/23/2024	TOR	vs	WPG	L 2-5	2	5	1	3	1	2	25	27
13	Maple Leafs	-3	12/21/2024	TOR	vs	NYI	L 3-6	3	6	0	0	0	0	29	34
14	Maple Leafs	-3	12/7/2024	TOR	@	PIT	L 2-5	2	5	1	3	2	5	27	29
15	Maple Leafs	-3	11/12/2024	TOR	vs	OTT	L 0-3	0	3	0	4	0	3	27	41
16	Maple Leafs	-3	10/19/2024	TOR	vs	NYR	L 1-4	1	4	0	3	0	2	35	29
17	Maple Leafs	-2	4/8/2025	TOR	@	FLA	L 1-3	1	3	0	2	0	1	18	37
18	Maple Leafs	-2	3/15/2025	TOR	vs	OTT	L 2-4	2	4	0	1	1	1	23	25
19	Maple Leafs	-2	1/29/2025	TOR	vs	MIN	L 1-3	1	3	0	1	1	1	33	25
20	Maple Leafs	-2	12/14/2024	TOR	@	DET	L 2-4	2	4	1	2	0	3	25	26
21	Maple Leafs	-2	12/6/2024	TOR	vs	WSH	L 1-3	1	3	0	2	0	4	21	26
22	Maple Leafs	-2	11/2/2024	TOR	@	STL	L 2-4	2	4	0	4	0	4	37	24
23	Maple Leafs	-1	3/13/2025	TOR	vs	FLA	L 2-3	2	3	0	3	2	3	25	25
24	Maple Leafs	-1	2/8/2025	TOR	@	VAN	L 1-2	1	2	0	2	1	2	28	25
25	Maple Leafs	-1	1/25/2025	TOR	@	OTT	L 1-2	1	2	0	1	1	2	29	23