Chris Rolfe was the hero as DC United defeated New England Revolution in a top-of-the-table clash.
DC United strengthened their hold on top spot in the Eastern Conference, while Real Salt Lake stunned Sporting Kansas City 2-1 in MLS.
A stoppage-time goal from substitute Olmes Garcia saw RSL triumph at home against Sporting, after the visitors had watched local goalkeeper Nick Rimando deny them an almost certain goal in the final half-hour.
Earlier, in Sunday's premier fixture, DC moved seven points clear in the East's standings with a come-from-behind 2-1 win over New England Revolution in the capital.
The Revolution made the trip to Washington for the top-of-the-table clash in the Eastern Conference and started strongly when Charlie Davies cleverly turned Lee Nguyen's cross into the net in the 10th minute.
But New England could not hold on for only their second win in nine matches, as Chris Rolfe's late brace dragged the hosts to victory.
Rolfe levelled the match in the 70th minute with a volley at the back post and then converted a penalty with nine minutes remaining, after Steven Neumann had fouled Miguel Aguilar in the box.
The win took DC to 31 points ahead of second-placed New England (24) and Orlando City (20), who sit third in the East.
In Utah, RSL hit the front in the 15th minute when Sebastian Jaime scored his maiden MLS goal with a header from Javier Morales' free-kick, but Sporting striker Dom Dwyer equalised on the half-hour mark after being teed up by Benny Feilhaber.
Dwyer thought he had put the visitors on top in the 64th minute but Rimando pulled off an incredible save to stop the Englishman's header, and that eventually cost Sporting all three points, after Garcia's 93nd-minute effort deflected into the net.comments