Pirates 1, Cubs 0 (10): Neil Walker homered to lead off the bottom of the 10th inning as Pittsburgh celebrated its first Opening Day walk-off home run since 1965.

Walker, who was 0-for-19 in last season's National League Division Series five-game loss to St. Louis, drilled a 3-2 fastball by Carlos Villanueva (0-1) over the wall in right. Pittsburgh's Bryan Morris (1-0), who was involved in a reversed call after an instant replay challenge, worked around a one-out single in the 10th inning to get the win.

Chicago nearly broke though in the eighth inning when Emilio Bonifacio, who went 4-for-5 in his Cubs debut, led off with a double and was sacrificed to third by Junior Lake before being retired 4-2-5-1-6-5 when caught in a rundown trying to score on Starlin Castro's grounder. Travis Ishikawa had two hits in his first game with the Pirates.

Both starters were sharp as Francisco Liriano, the ninth different Opening Day starter in nine years for the Pirates, allowed four hits and struck out 10 in six innings. Chicago's Jeff Samardzija, who pitched eight shutout innings in the Cubs' 3-1 victory on Opening Day in Pittsburgh last season, allowed five hits in seven frames.

The call was reversed in the 10th inning after first base umpire Bob Davidson signaled Bonifacio safe after Morris' pickoff attempt. Pirates manager Clint Hurdle challenged the call and after a few minutes, crew chief John Hirschbeck discovered during the review that Ishikawa's tag preceded Bonifacio's hand touching the base.

GAME NOTEBOOK: The first instant replay challenge in Major League Baseball history occurred in the fifth inning when Cubs manager Rick Renteria questioned whether Samardzija was out at first after bunting into a double play in the fifth inning. The review quickly confirmed Davidson's ruling. ... Liriano tied a Pittsburgh record for most strikeouts on Opening Day, previously accomplished by Bob Veal (1965, a complete-game 1-0 Pirates victory on Bob Bailey's home run off Juan Marichal in the 10th inning), John Candelaria (1983) and A.J. Burnett (2013). ... Pirates CF Andrew McCutchen was honored prior to the game for winning the 2013 National League MVP trophy in a ceremony which included former Pittsburgh greats Dick Groat (1960 NL MVP) and Barry Bonds (1990 and 1992 NL MVP).