CHESTER, Pa. (973espn.com) – After an uninspired first half, the Philadelphia Union came roaring back to top the New York Red Bulls, 2-1, in the Round of 16 of the 2016 Lamar Hunt U.S. Open Cup at Talen Energy Stadium.

The Union were sloppy from the opening kick as New York dominated the early action, going on top in the 17th minute when a Richard Marquez clearing attempt wound up on the foot of Mike Grella, who beat Philadelphia goalkeeper Andre Blake easily from the top of the box.

Things could of, and probably should have, been worse for the Union by the break if not for the acrobatic Blake.

"We went down a goal and I just knew that we were still in the game, so I knew that I had to work harder to try to keep it at one," Blake said. "I knew that at some point, we’d get some chances."

New York had a stunning 14 shots, including six on target, in the first 45-plus minutes with Blake making five different saves. Conversely the Union mustered one shot on Red Bulls GK Ryan Meara.

The failure to cash in on so many opportunities came back to bite NY, however.

After no doubt a few stern words by Union coach Jim Curtin at intermission, Philadelphia emerged from the locker room with a purpose in the second half and evened things in the 55th minute after Ilsinho delivered a great ball in the path of the club's leading goal scorer, Chris Pontius, who slid the ball past a helpless Meara.

The Union's used the same formula five minutes later to go on top for good as Ilsinho chipped a perfect cross right on the left foot of Pontius, who sent it home again.

"We were just a lot cleaner in the second half," Pontius said. "In the first half, we weren’t clean on anything – our combination play, our passes when we did break out of press. We just made the wrong decision."

From there Philadelphia was able to hold off New York but not before some fireworks from Red Bulls coach Jesse Marsch, who was ejected during stoppage time for arguing with referee Mark Kadlecik.

Marsch was so incensed he picked up a pair of soccer balls and hurled one of them toward the Union bench before walking out to the serenades of a@#$%^& from the Sons of Ben at the River End.

"I had to try and induce change with the referee somehow because he was basically calling every foul for the Union." Marsch said. "So, laughable."

Philadelphia is now a gaudy 10-2 in Open Cup competition since Curtin took over the club. In each of the prior two seasons, Philadelphia has reached the final. And, in each of the last four years, the club has lost to the eventual champions.

"I thought it was a tale of two halves," Curtin said. "It was not us in the first half, we were disappointed with it and the players responded really well in the second half and pushed the tempo of the game."

The Union will now move on to face the New England Revolution in the quarterfinals of the Open Cup on July 20. Philadelphia returns to MLS action in Houston on Saturday.

-John McMullen covers the Philadelphia Union for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen.