Instant analysis: Homestead

Brad Keselowski started the NASCAR season as a Twitter sensation in the opening Daytona 500, tweeting from his car during a red flag.

He ended it as the Sprint Cup champion in the season finale at Homestead-Miami Speedway, no doubt adding more Twitter followers when he claimed the crown.

The title was in doubt most of the day between Keselowski and five-time champ Jimmie Johnson, but here's a look at how it went down in the Ford 400 Sunday, and what it means for NASCAR:

A new champ: For the first time in six years, NASCAR has a first-time Cup champion. Keselowski is the first new champ since Johnson won his first of five consecutive titles in 2006.

A racing legend earns a Cup title: Roger Penske, one of the most respected team owners in auto racing history, finally earned that elusive Cup title. "This is the pinnacle of achievements that we can get in motor racing," Penske said, a man with 15 Indy 500 trophies.

A big mistake that didn't matter: Surprisingly, it was made by the No. 48 Chevy crew when Johnson left his pit box without all the lug nuts on one of his tires with 54 laps to go. Johnson was leading when he pitted. But he had to return to pit road and fell back to 25th, virtually ending his chances of winning the title.

The deciding moment: The pit crew mistake proved meaningless. Johnson's day ended 14 laps later, when he coasted back to pit road with a broken rear-end gear.

Brad's reaction: When Keselowski was told Johnson was back in the garage, he said, "Are you sure?" He was told yes and Keselowski said, "Then let's race." Keselowski finished 15th, which meant he would have won the title no matter what Johnson did.

Most nervous lady: Kathy Penske, Roger's wife, rapidly tapping her foot on the pit box and looking concerned while watching Keselowski in the final laps.

And the race winner was: Jeff Gordon -- one week after one of the most embarrassing moments of his stellar career, when he intentionally wrecked Clint Bowyer -- wins the race, the first time a Hendrick Motorsports driver ever won at Homestead.

And the championship runner-up was: Not Johnson. It was Bowyer, who finished second Sunday and ended up one point ahead of Johnson.

First tense moment: Keselowski and Johnson running side-by-side on Lap 61 of the 267-lap race. Both drivers stayed clean as Keselowski moved in front of Johnson.

Smart decision: Keselowski let Johnson go by him on Lap 75 after Johnson stalked him from behind for 12 laps. No reason for Keselowski, who started the day with a 20-point lead, to risk making contact with Johnson in that situation.

First mistake: On a pit stop during the first caution, Keselowski's pit crew had a problem with a lug nut on the right rear tire. Keselowski entered the pits one spot behind Johnson, but Keselowski restarted 14th and Johnson restarted sixth on Lap 84.

Tense non-championship moment: Gordon was running fifth, one spot behind Bowyer on Lap 104. Gordon was fined $100,000 and docked 25 points for wrecking Bowyer last week, which started a garage melee. On Sunday, Bowyer raced him clean as Gordon made a move down low to get by him.

Meanwhile, up front: Martin Truex Jr. passed Kyle Busch for the lead on Lap 117, proving drivers actually do make passes up front on the much-maligned 1.5-mile ovals. It was one of many up-front passes on the day.

First strategic move among the contenders: Crew chief Chad Knaus elected to change only two tires during a pit stop under caution at Lap 145. Crew chief Paul Wolfe elected for his crew to change all four tires for Keselowski. Johnson restarted first and Keselowski restarted 15th. At that moment, Johnson trailed Keselowski by only two points.

Tied at the top: One lap after that restart, the two title contenders were tied in the points standings (momentarily) before Keselowski passed a couple of cars.

Second strategic move: During a caution on Lap 158, Johnson pitted while leading and the crew changed the left-side tires. Keselowski stayed out and restarted seventh. Johnson restarted ninth. But Johnson zoomed by Keselowski on the first turn and Keselowski went backwards. Johnson was sixth and Keselowski was 12th two laps later.

More great racing up front: Kyle Busch and Kasey Kahne traded the lead four times on Laps 167 and 168.

Dodging a bullet: Keselowski almost stayed out one lap too many with 62 laps to go. Keselowski came around Turn 3 and told Wolfe, "Out of gas, coming in." He wasn't completely out of fuel because the No. 2 Dodge made it to the pit stall under power. It briefly gave Johnson the championship lead by seven points with 56 laps to go before he pitted two laps later, and that was the beginning of the end for Johnson.