In the heart of summer, after months of traveling the continent in search of precious away points, D.C. United opened a new stadium on a forgotten slice of land in the southwest sector of the city.

United sat last in MLS’s Eastern Conference, a spot it had occupied for two months because of an incomplete roster and a place the club would keep for the time being because it had played far fewer matches than everyone else.

But since mid-July, as the schedule accelerated and Buzzard Point became a haven for the high-scoring home team, United has climbed the standings and surged into playoff contention.

The 5-0 victory over the Montreal Impact on Saturday — United’s most lopsided triumph in 17 years — left Ben Olsen’s squad two points behind the Impact for the sixth and final slot in the conference.

With this weird 2018 schedule turning in its favor — two fewer games played than the Impact and four of the last five at Audi Field — D.C. is now favored to reach the postseason.

“To see this group in the form they’re in and to be in the conversation for playoffs is a good feeling,” Olsen said. “We knew we were going to struggle a bit at the start, but we had an opportunity to get some wins at home and make progress.”

He cautioned, however, “this win doesn’t do any good if we don’t take care of Chicago next weekend.”

Chicago, which has been eliminated from the playoff hunt but has performed well of late, bookends United’s last five matches: this Sunday afternoon in Washington and Oct. 28 at Toyota Park in Bridgeview, Ill.

In between, United will brace for three problematic home matches: playoff-bound FC Dallas; Toronto FC, a desperate but dangerous defending champion; and New York City FC, which, if it remains third in the Eastern Conference, would host D.C. in a single first-round playoff Oct. 31 or Nov. 1 at Yankee Stadium.

The Dallas and Toronto games fall during international call-ups, which will leave United undermanned.

Montreal will close with home dates against Columbus and Toronto and a visit to New England. The latter two are chasing the Impact and United, three and five points respectively behind D.C.

Atlanta and the other New York area team, the Red Bulls, have also clinched berths, while Columbus and Philadelphia are getting close. The chances of D.C. or anyone else climbing above sixth place are remote.

Nonetheless, United is playing like a high seed. It has taken 24 points from the past dozen matches and, with a 3-0-2 run, holds the longest current unbeaten streak in the league.

Things have been particularly good at Audi Field, where D.C. has scored 27 goals in 11 appearances. And in two of those games, United did not score at all. It has scored at least three goals six times.

While playing at home in a compact stadium has been beneficial, the personnel — and the chemistry the players have bred — are the reasons for the success there.

Wayne Rooney, the English superstar, arrived in time for the venue opening. Goalkeeper Bill Hamid returned from Denmark a few weeks later. Russell Canouse recovered from a long injury layoff to form a bond in defensive midfield with Junior Moreno.

No one has enjoyed the last few months more than central midfielder Luciano Acosta, who has recorded eight goals and eight assists at Audi Field. On Saturday, he scored the opener and assisted three times in the second half. In the past three games, the 24-year-old Argentine has posted six assists to raise his total to a league-best 16.

In 15 appearances, Rooney has contributed seven goals (all at home) and seven assists (all but one at home). He and right wing Paul Arriola scored two apiece against Montreal.

Saturday’s good vibes, however, were dampened by a potentially serious injury to defender Oniel Fisher, who has started all but three matches since May. Early in the second half, after making a poor back pass, he collided with Hamid and reached for his right knee.

United will await results of an MRI exam. If Fisher is sidelined for an extended period — or, for that matter — the rest of the season, Olsen will turn to newly acquired Kevin Ellis, Jalen Robinson or Nick DeLeon, who is close to returning from a long-term knee injury. Arriola has provided cover on the back line, but with the attack clicking, Olsen seems less inclined to further alter the lineup.