New York Red Bulls defeated DC United thanks to Kaku's long-range effort, while Seattle Sounders extended their winning streak to seven games.
Alejandro Romero Gamarra – better known as Kaku – was the hero as his thunderous second-half effort lifted the high-flying Red Bulls past DC 1-0 in MLS on Sunday.
Wayne Rooney's DC had gone five matches without defeat to move into play-off contention but that changed at Red Bull Arena, where the former Manchester United and England captain almost scored from a free-kick in the ninth minute.
DC enjoyed some great opportunities to make the breakthrough before half-time – Oniel Fisher's header sailing over the crossbar from point-blank range.
However, the Red Bulls – riding a four-match unbeaten streak – took the lead 10 minutes into the second half when Kaku riffled a shot past Bill Hamid.
And the Red Bulls managed to hold on for all three points after Rooney hit the post during the latter stages of the second half.
With the win, the Red Bulls moved within two points of Eastern Conference leaders Atlanta United, while DC remain eighth and six points outside of the play-off spots.
In Portland, the Sounders stayed hot with a hard-fought 1-0 victory away to the Timbers.
An own goal from Julio Cascante gifted the Sounders the win and condemned the Timbers to a fourth consecutive defeat.
The surging Sounders are now up to fifth in the Western Conference on 38 points. Meanwhile, the Timbers have fallen behind their Cascadia rivals, into seventh place on 37 points.