Kershaw was his same old dominant self on Opening Day. (SD Dirk/Creative Commons)

Pop open the champagne and begin the summer-long party as the baseball season took to the field on Monday, starting the 2013 season. Opening Day showcased some strong pitching performances, individual power displays, and a bunch of surprises along the way.

Twelve games were played Monday kicking off the baseball festivities to the delight of sold out crowds to passionate fan bases across the country. On a day in which every team still had a shot to hold possession of first place in their division, nothing can be greater than the whirlwind of emotions Opening Day unlocks.

Here are some of the key storylines from April Fools Day Baseball that was anything but a laughing matter. First and foremost Interleague Play is here to stay, with games set for every day on the calendar.

1. Clayton Kershaw Will Earn Every Penny In Next Contract

Dodgers ace Clayton Kershaw followed the teams elite lineage of left-handed studs, pitching a performance comparable to the likes of Sandy Koufax.

Kershaw threw a complete game shutout, while also hitting a home run to spark the offense. Kershaw was the first pitcher since 1988 to homer on Opening Day, a year special to all Dodgers fans as the last World Series Championship.

The Dodgers ace looked like the same 2011 Cy Young Winner and 2012 NL ERA Champion on the mound, with even more confidence early on this season. The Giants could never mount a decent rally as Kershaw continued to pound the zone with first-pitch strikes and ridiculous breaking pitches that made Vin Scully chuckle in the press box.

The start could not have come at a better time for Kershaw, who is currently set to be a free agent at the end of next season. Both parties would love to sign a long-term deal before the end of the year, and this type of performance will place Kershaw above the five-year, $140 million deal Justin Verlander signed last week.

2. Red Sox Look Wise to Call Up Jackie Bradley Jr. 

After much anticipation over his arrival on the 25-man roster, highly-touted prospect Jackie Bradley Jr. started Opening Day for the Boston Red Sox. The 22-year-old rookie was all the craze during Spring Training, hitting over .400 for the club, utilizing his speed and patience to dominate the Grapefruit League.

Red Sox ownership made a bold move placing Bradley on the roster because if Boston kept him off the opening day roster for 11 days, they would earn an extra year of arbitration. This basically means Bradley would be paid less than his market value for an extra year in Fenway.

Bradley only played half a season in Double-A last year, but made quite the impact in his MLB debut in left field against the rival New York Yankees. In his first at-bat, Bradley fell behind to 20-game winner C.C. Sabathia 0-2 but fought his way out of the hole to work out a walk. Patience was common throughout the day as Bradley coerced three walks and scored twice in the Red Sox victory.

3. Pitching Came to Play On April Fools' Day

Typically on Opening Day the bats come alive as pitchers traditionally take longer to find their groove with their breaking pitches and delivery. This year, however, was a different story as pitchers and catchers reported to camp nearly a month before the start of the season, and eight days earlier than usual preparing for the World Baseball Classic. 

Opening Day was loaded with pitchers' duels, sparking the conversation of pitching dominance looming in 2013. Jeff Samardzija threw an outstanding game against Pittsburgh, striking out nine in eight innings, not to mention his counterpart A.J. Burnett powered down 10 Cubs hitters. Although it is a small sample size, seven of the twelve games played on Opening Day featured scores in which both teams registered four runs or less.

Ian Kennedy, Felix Hernandez, James Shields, Chris Sale, Jon Lester, Jered Weaver and Justin Verlander were just some of the names who dominated on the mound in their first start of the season. Ten starting pitchers went at least six innings of work in the National League, while six pitchers could claim the feat in the AL with ERA less than 2.75 in those starts. 

Bryce Harper is making his bid for NL MVP right away. (MissChatter/Creative Commons)

Sophomore sensation Bryce Harper took the field in Washington D.C. in the cleanup spot, and man, did he deliver for the Nationals. Harper crushed two Ricky Nolasco breaking balls into the right-field seats plating, the only runs of the day for the victorious Nats.

The 20-year-old Harper looked polished at the plate in his 140th game of his career, taking the next step to succeed in the big leagues. In a sport where adjustments are crucial, Harper showcased his ability to drive off-speed pitches while remaining patient at the dish. Harper watched 15 pitches in four at-bats, but also hit .500 on the afternoon.

The addition of Denard Span over the offseason allowed Harper to make the full-time switch to left field, a move that paid dividends for head coach Davey Johnson. Harper recorded a double-play, throwing out a would-be scorer in Giancarlo Stanton at the plate. As the season progresses, expect the superstar left fielder to continue taking mammoth hacks and full-throttle sprints toward continued success.

5. Angels Bullpen Dominant In Extra Inning Victory

The Los Angeles Angels of Anaheim exhibited a much-needed improvement in their bullpen, notching quite a dominant performance in their 13-inning marathon victory over the Cincinnati Reds.

Angels starting pitcher Jered Weaver left the tied contest in the sixth inning, leaving the rest of the work to a bullpen that struggled to get hitters out last season, ranking fourth in the league in blown saves (22) and 22nd in MLB bullpen ERA (3.97).

This unit picked up some key pieces from the NL East the offseason, in Ryan Madson and former reliever Tommy Hanson, alongside former Rangers pitcher Mark Lowe. Despite the additions, the Angels traditional bag of tricks played themselves out for Mike Scioscia on Opening Day. 

The bullpen threw seven shutout innings, allowing only one hit while striking out nine Reds hitters. Lowe had the biggest impact on the contest, pitching two innings of relief in the 11th and 12th, striking out three batters to preserve the game for closer Ernesto Frieri to seal the victory in the final frame.

The Angels will need this type of performance from their bullpen to complement their new starting rotation. The additions of Tommy Hanson, Joe Blanton and Justin Vargas are solid, but these men will by no means be innings eaters for the Halos.

Reach Staff Writer Evan Budrovich here, or follow him on Twitter.