BOSTON -- J.D. Martinez kept his hands tight toward his body, snapping his wrists forward as he uncoiled his swing. The ball was a hair off the plate and a tick shy of 94 mph, a difficult pitch for most hitters to do much with other than pull it foul.
From their perspective atop the Green Monster, a cluster of fans knew immediately that Martinez had kept it plenty fair. One stuck his arm into the air as the three-run homer landed in his glove. His companion wrapped him in a bear hug, elated without knowing that Martinez's blast would be the difference in the Red Sox's 5-4 win over the Yankees on Friday night in Game 1 of the American League Division Series.

:: ALDS schedule and results ::
With that swing, Martinez not only put his team on an early path to victory, but he continued the process of vindicating Boston's five year, $110 million investment in him.
"Obviously I was a little bit more pumped up than every other home run I hit during the season," Martinez said. "That's just because of the stage."
Considering Boston's bullpen would later threaten to unravel Martinez's work, the outfielder's first-inning homer provided some needed cushion. After Andrew Benintendi singled and stole second base with one out, Steve Pearce walked to bring up Martinez. Yankees starter J.A. Happ threw him a fastball inside and another low, before delivering a third heater off the inner edge of the plate.
The result was Martinez's 45th homer in 151 games with the Red Sox, counting the regular season, and his first extra-base hit in 21 career at-bats against Happ. He entered the night 4-for-20 with four singles off the left-hander.
"My execution wasn't as sharp as it's been," Happ said. "The big hit cost me."
The big hit also gave Martinez four home runs, five extra-base hits and nine RBIs in eight career postseason games. He hit a home run in each of his first two playoff appearances with the Tigers in the 2014 ALDS, then another for the D-backs in last year's National League Division Series.

Boston's marquee offseason addition, Martinez batted .330 with a 1.031 OPS in his first season with the club. His 130 RBIs led the Majors, but meant little heading into the ALDS.

"It's definitely a different feeling," Martinez said. "Everything you did before in the season doesn't matter anymore. This is the playoffs. From here on out, everything starts at zero. Look at the scoreboard, all your numbers are zero, zero, zero. So you know what's at stake."