The win for Boston moves them a season-high six games over the idle New York Yankees for the top spot in the AL East. They hold baseball's best record at 75-33, as they recorded their 38th win at home in their 52nd game at Fenway Park this season.
Hector Velazquez threw a scoreless inning to improve to 7-0 on the season, while Austin Davis suffered his first loss for Philly. Davis allowed Nunez's leadoff single, while Luis Garcia gave up the game-winning hit. Garcia was the 12th pitcher used in the four-plus hour contest.
Swihart's double was his first-career walk-off hit, sending Boston to their 19th win in the past 23 games. They are now 42 games over .500 for the first time since the end of the 1946 season. The Bosox have also had interleague success as of late, winning 19 of their past 21 against National League teams.
Both starting pitchers threw gems on this night, as David Price went eight innings and struck out five, while Aaron Nola also went eight and struck out six. Both pitchers received no-decisions despite holding the opposing team to just one run.
Maikel Franco had the lone Phillies RBI with a single in the second inning. Nunez would tie things up with an RBI triple in the fifth inning. These two teams will do battle again on ESPN Tuesday night.