During New York's 3-2 win over the Union on May 13 at PPL Park, the 6-foot-3, 207-pound Cooper scored the game-winning goal.
"He is not only big, he knows how to make runs, to sneak in behind the center backs or the wide backs," Union defender Amobi Okugo said of Cooper.
As for Le Toux, it was his third game as a Red Bull since being acquired July 13 from Vancouver. He played for Vancouver in a scoreless draw against the Union on March 31 at PPL Park.
"That was more emotional, going back to PPL Park," Le Toux said. "Now it was great to see the guys, but it was different."
Le Toux played the entire game and made some nice runs, but it was Cooper who stole the show.
In the 20th minute, Union keeper Zac MacMath stopped a shot from Copper from just outside the box. Le Toux got the rebound but fired well over the cross bar from 14 yards out. Late in the game, MacMath came off his line and beat Le Toux to the ball on a potential breakaway.
Cooper opened the scoring when he headed in a cross from Connor Lade inside the near post in the 43d minute.
He was just warming up.
In the 58th minute, Cooper headed a chip from Thierry Henry for his 13th goal of the season.
The Union did a good job holding possession in the first half. The second half was a different story.
"We dominated in the first half but didn't have anything to show for it," defender Gabe Farfan said.
Dominated may be too strong of a word, but the Union had their moments in both halves.
"I thought we did an OK job trying to control the tempo and rhythm," Union interim team manager John Hackworth said. "We were not so good in the final third. Our last pass evaded us all night."
The Union's best first-half chance came when Michael Farfan sent Josue Martinez on goal only to have New York keeper Bill Gaudette stone him on the breakaway in the 40th minute.
Union forward/midfielder Freddy Adu missed the game due to an undisclosed matter, according to a team official.
Hackworth said Adu will probably be ready for the Union's next game, July 29 at PPL Park against New England.
Contact Marc Narducci at 856,779-3225, firstname.lastname@example.org or @sjnard on Twitter.