Jermaine O'Neal is the youngest in a game with 20+ points. He was 18 years and 101 days old versus the Seattle SuperSonics on January 22, 1997.

the youngest player in nba history to score 20 points in a single regular season game

Interpreted as:

the youngest player in NBA history to score 20 or more points in a single regular season game

NAME	AGE	PTS	DATE	TM		OPP	MIN	REB	AST	STL	BLK	TOV	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	PF	+/-
Jermaine O'Neal	18-101	20	1/22/1997	POR	@	SEA	25	6	0	0	2	1	8	10	80.0	0	0		4	4	100.0	4	+19
Kobe Bryant	18-133	21	1/3/1997	LAL	vs	SAC	22	5	1	2	2	0	6	10	60.0	0	2	0.0	9	10	90.0	1	+10
Kobe Bryant	18-148	21	1/18/1997	LAL	vs	DET	32	2	5	1	0	4	8	13	61.5	3	5	60.0	2	2	100.0	1	-1
Kobe Bryant	18-216	20	3/27/1997	LAL	@	VAN	43	8	4	3	0	3	6	16	37.5	1	5	20.0	7	7	100.0	3	+14
Kobe Bryant	18-228	24	4/8/1997	LAL	@	GSW	25	2	3	1	0	5	9	11	81.8	2	3	66.7	4	7	57.1	3	+23
Tracy McGrady	18-265	22	2/13/1998	TOR	@	NJN	37	8	1	1	1	1	7	16	43.8	0	0		8	10	80.0	1	-9
LeBron James	18-303	25	10/29/2003	CLE	@	SAC	42	6	9	4	0	2	12	20	60.0	0	2	0.0	1	3	33.3	3	-9
LeBron James	18-304	21	10/30/2003	CLE	@	PHX	41	12	8	1	0	7	8	17	47.1	1	5	20.0	4	7	57.1	1	-3
LeBron James	18-312	23	11/7/2003	CLE	@	IND	44	5	3	0	0	7	8	18	44.4	1	2	50.0	6	7	85.7	2	-7
LeBron James	18-320	22	11/15/2003	CLE	vs	PHI	47	5	8	1	2	5	10	19	52.6	0	1	0.0	2	4	50.0	2	+8
Tracy McGrady	18-323	20	4/12/1998	TOR	vs	NJN	35	7	6	3	1	3	9	13	69.2	0	0		2	2	100.0	2	-15
LeBron James	18-324	28	11/19/2003	CLE	@	WAS	40	7	8	2	1	4	10	18	55.6	2	4	50.0	6	8	75.0	2	-5
Bill Willoughby	18-326	20	4/10/1976	ATL	vs	PHI	42	18	4	2	3		7	14	50.0				6	11	54.5	2
LeBron James	18-334	33	11/29/2003	CLE	vs	MEM	55	16	7	1	1	8	14	28	50.0	3	6	50.0	2	3	66.7	1	-10
LeBron James	18-346	23	12/11/2003	CLE	vs	DET	43	3	9	1	1	4	8	21	38.1	1	3	33.3	6	8	75.0	3	+9
LeBron James	18-348	37	12/13/2003	CLE	vs	BOS	45	3	4	0	0	2	10	20	50.0	1	5	20.0	16	18	88.9	2	-2
LeBron James	18-350	27	12/15/2003	CLE	@	IND	44	4	6	3	3	6	10	16	62.5	0	3	0.0	7	8	87.5	1	-12
Dwight Howard	18-354	24	11/26/2004	ORL	@	ATL	42	9	2	2	0	4	8	11	72.7	0	0		8	12	66.7	2	+12
LeBron James	18-354	36	12/19/2003	CLE	@	PHI	42	4	5	4	0	4	14	24	58.3	5	7	71.4	3	3	100.0	1	+9
LeBron James	18-355	32	12/20/2003	CLE	@	CHI	42	6	10	2	2	4	11	22	50.0	0	5	0.0	10	12	83.3	2	+9
LeBron James	18-358	22	12/23/2003	CLE	vs	NOH	39	6	2	6	1	5	7	22	31.8	1	6	16.7	7	8	87.5	1	+9
LeBron James	18-360	34	12/25/2003	CLE	@	ORL	47	2	6	2	1	8	13	28	46.4	4	10	40.0	4	5	80.0	0	-9
LeBron James	18-363	32	12/28/2003	CLE	vs	POR	39	10	9	3	0	5	15	23	65.2	0	2	0.0	2	2	100.0	1	+11
Dwight Howard	18-364	23	12/6/2004	ORL	@	DEN	42	10	4	4	0	4	7	12	58.3	0	0		9	15	60.0	0	-4
LeBron James	19	22	12/30/2003	CLE	vs	IND	38	10	4	0	0	4	9	20	45.0	0	4	0.0	4	6	66.7	2	-2