Allen ran in a time of 13.04 seconds -- tied for the fourth-fastest in the world this year -- and finished second behind Daniel Roberts, who had a 13.01.
Allen has improved his time in each of the five 110-meter hurdles he has competed in this year, starting with the event at the Penn Relays, where he won with a time of 13.46 in April.
Allen, 28, spent last season on the Eagles' practice squad after signing with the team in April. Before that, he had last played football for the University of Oregon in 2016. He had put his football career on hold to pursue track and field and finished fifth and fourth in the 110-meter hurdles in the past two Olympics.
He was asked on the NBC Sports broadcast about how he is managing juggling football plus track and field.
"It's going well. You know, balancing both is difficult, but I'm having a lot of fun," he said. "As long as I can stay healthy, it's good to compete against these guys in high-quality competition. You know, 13.01 and 13.04 is nothing to scoff at, so we're ready to go."
He also ran in track events last year after signing with the Eagles and ran his personal-best time of 12.84 seconds in the 110-meter hurdles -- third-fastest in the world ever -- in winning the event at the USATF NYC Grand Prix.
Allen will next compete at the USATF Outdoor Championships, scheduled for July 6-9 in Eugene, Oregon. If he were to qualify for the world championships, which will take place Aug. 18-27 in Budapest, Hungary, he has said he will have a decision to make.
"Yeah, I still don't have a plan of what I'm going to do with worlds being, you know, during training camp," Allen told KPIC-TV in Oregon ahead of the NYC Grand Prix. "Obviously, it'd be nice to compete at worlds and also it would be nice to be at training camp so I can make the 53-man roster. So, obviously it's going to be a little bit of a decision, but I'm not going to worry about that, like I said, until I make the world championship team. USA is a competitive meet. Just got to focus on doing that first."