Jacquelyn Martin/AP

Fans were still filing into Nationals Park on Monday night, but as starter John Lannan trudged to the bullpen with pitching coach Steve McCatty to warm up nearly half an hour before first pitch, the building crowd cheered louder than their size would suggest. Fans have done this for other starters before – most commonly for Stephen Strasburg and Gio Gonzalez – but not often for Lannan in his few starts this season.

The excitement and crowds were building for this: the Nationals chance at clinching their first-ever National League East title at home against the Philadelphia Phillies.

Lannan allowed a leadoff single to Phillies third baseman Kevin Frandsen. But wiggled out of it by getting John Mayberry to ground into a double play. The stands, with few large swaths of empty seats, erupted. After the first inning ended, the fans around the home dugout stood, clapped and shouted as the players ran into the dugout. By the second inning, there were more red and white shirts dotting the upper decks than empty blue seats.

It was early but the energy was already evident. It also felt different than in previous seasons when Phillies fans jammed Nationals Park at this time of the year to see their team clinch a division title.

The crowd almost begged the Nationals to do something by the fifth inning when, facing a 2-0 deficit and little offense against Phillies starter Kyle Kendrick, Kurt Suzuki reached on a single. An errant pickoff throw by Kendrick moved him to third base. With two outs and a 2-2 count against Jayson Weth, the crowd was boisterous and on its feet. (Werth, by the way, struck out looking to end the inning.)