Ryan Blaney tops first Cup practice at Chicagoland

Jimmie Johnson set the pace early in the session at 178.861mph, just ahead of young teammate Alex Bowman at 178.749mph.

But in the final seconds of the 50 minute practice, Team Penske's Ryan Blaney rocketed to the top of the charts on his 14th lap, putting up a 178.992mph lap.

Johnson also ran the most laps at 31, telling NBCSN afterwards, "really impressed with the way we unloaded and how this Chevrolet is driving."

Chase Elliott, Daniel Suarez, Ryan Newman, Denny Hamlin, Kyle Larson, Joey Logano, and Jamie McMurray rounded out the top-ten.

Defending race winner Martin Truex Jr. was down in 19th on the speed charts.

The session went incident-free. Two drivers -- Landon Cassill and B.J. McLeod -- were given 15-minute practice holds for being late to inspection.

Cla	#	Driver	Manufacturer	Laps	Time	Gap	Interval	Mph
1	12	Ryan Blaney	Ford	14	30.169			178.992
2	48	Jimmie Johnson	Chevrolet	31	30.191	0.022	0.022	178.861
3	88	Alex Bowman	Chevrolet	29	30.210	0.041	0.019	178.749
4	9	Chase Elliott	Chevrolet	26	30.210	0.041	0.000	178.749
5	19	Daniel Suarez	Toyota	20	30.384	0.215	0.174	177.725
6	31	Ryan Newman	Chevrolet	24	30.432	0.263	0.048	177.445
7	11	Denny Hamlin	Toyota	20	30.447	0.278	0.015	177.357
8	42	Kyle Larson	Chevrolet	20	30.457	0.288	0.010	177.299
9	22	Joey Logano	Ford	22	30.499	0.330	0.042	177.055
10	1	Jamie McMurray	Chevrolet	28	30.499	0.330	0.000	177.055
11	4	Kevin Harvick	Ford	20	30.554	0.385	0.055	176.736
12	41	Kurt Busch	Ford	20	30.578	0.409	0.024	176.598
13	2	Brad Keselowski	Ford	22	30.627	0.458	0.049	176.315
14	14	Clint Bowyer	Ford	23	30.664	0.495	0.037	176.102
15	21	Paul Menard	Ford	17	30.664	0.495	0.000	176.102
16	10	Aric Almirola	Ford	28	30.709	0.540	0.045	175.844
17	6	Trevor Bayne	Ford	12	30.748	0.579	0.039	175.621
18	18	Kyle Busch	Toyota	9	30.754	0.585	0.006	175.587
19	78	Martin Truex Jr.	Toyota	20	30.783	0.614	0.029	175.421
20	37	Chris Buescher	Chevrolet	19	30.840	0.671	0.057	175.097
21	43	Darrell Wallace Jr.	Chevrolet	30	30.861	0.692	0.021	174.978
22	3	Austin Dillon	Chevrolet	28	30.865	0.696	0.004	174.955
23	24	William Byron	Chevrolet	24	30.896	0.727	0.031	174.780
24	13	Ty Dillon	Chevrolet	19	30.944	0.775	0.048	174.509
25	20	Erik Jones	Toyota	16	30.982	0.813	0.038	174.295
26	47	A.J. Allmendinger	Chevrolet	20	31.100	0.931	0.118	173.633
27	17	Ricky Stenhouse Jr.	Ford	24	31.107	0.938	0.007	173.594
28	34	Michael McDowell	Ford	20	31.133	0.964	0.026	173.449
29	32	Matt DiBenedetto	Ford	13	31.266	1.097	0.133	172.712
30	38	David Ragan	Ford	9	31.447	1.278	0.181	171.717
31	95	Kasey Kahne	Chevrolet	17	31.503	1.334	0.056	171.412
32	15	Ross Chastain	Chevrolet	15	31.572	1.403	0.069	171.038
33	23	Gray Gaulding	Toyota	8	31.902	1.733	0.330	169.268
34	72	Corey Lajoie	Chevrolet	6	32.231	2.062	0.329	167.541
35	07	Reed Sorenson	Chevrolet	16	32.252	2.083	0.021	167.431
36	00	Landon Cassill	Chevrolet	8	32.283	2.114	0.031	167.271
37	66	Timmy Hill	Toyota	6	32.380	2.211	0.097	166.770
38	99	Kyle Weatherman	Chevrolet	16	32.854	2.685	0.474	164.364
39	51	B.J. McLeod	Ford