WASHINGTON -- Bartolo Colon allowed just one run in six innings and the New York Mets beat the defending East Division champion Washington Nationals 3-1 on Monday on Opening Day in the nation's capital before a sellout crowd of 42,295.

Colon allowed just three hits with eight strikeouts as he beat Washington starter Max Scherzer, who did not allow a hit in the first five innings.

But the Mets scored three unearned runs off Scherzer as Washington shortstop Ian Desmond, who will be a free agent after this season, made two errors that led to the three runs.

Mets first baseman Lucas Duda had a two-run single in the sixth with two outs to give his team a 2-1 lead on the first hit of the day for New York. The hit came after Desmond dropped a popup in short center for a two-base error.

New York catcher Travis d'Arnaud gave the Mets a 3-1 lead in the seventh as he hit a triple to center to score Juan Lagares, the Mets' center fielder who had reached on a throwing error by Desmond to lead off the frame.

Washington right fielder Bryce Harper hit a solo homer to lead off the fourth against Colon to give the Nationals a 1-0 lead. Harper hit two homers on Opening Day in 2013 but was limited to 100 games last year due to injuries.

Harper lined out to lead off the ninth against Mets reliever Jerry Blevins, a former teammate who was traded by Washington to New York last week. Buddy Carlyle then retired first baseman Ryan Zimmerman and catcher Wilson Ramos for the last two outs on grounders as the Nationals were held to three hits.

Scherzer gave up three unearned runs and four hits with eight strikeouts. He was lifted with two outs in the eighth for lefty reliever Xavier Cedeno, who ended the inning by retiring second baseman Daniel Murphy with two runners on base.

NOTES: New Major League Baseball commissioner Rob Manfred announced before the game that Washington has been awarded the 2018 All-Star Game. Manfred noted it will be the fifth time Washington has hosted the game and the first time since 1969. "Just a great bid. Truly compelling," he said of the Nationals' presentation. A former resident of Washington, D.C., Manfred noted 2018 will be the fourth year in a row that the National League will host the event. "We are comfortable with that. We will bring a great show in 2018." Mark D. Lerner, part of the ownership group, said the Nationals started lobbying for the game about "10 minutes" after they were awarded the franchise. "It's a great day and we are delighted to have the game," he said. ... Mets third baseman David Wright started and batted second in his 11th Opening Day for the Mets, tying Tom Seaver and Bud Harrelson for the franchise record. Where does he want to hit in the order? "Best (spot) to help the team win. It doesn't matter," he said. ... The starters in the second game of the series are Washington right-hander Jordan Zimmermann (14-5, 2.65 in 2014) against Mets' right-hander Jacob deGrom (9-6, 2.69). ... Ryan Zimmerman made his first Opening Day start at first base for the Nationals. He won the Gold Glove at third in 2009. "It is an exciting day. But you have to treat it like any other game," he said.