The Arabs equipped themselves well during a low key first half and would have had a shock win in their sights as Michael Beale’s side failed to fire in the final third.
But Fashion Sakala and Malik Tillman struck within a couple of minutes of each other as Rangers turned the game in the opening stages of the second period.
The visitors were well worthy of their win in the end as they ensured they didn’t fall further behind Old Firm rivals Celtic in the Premiership title race.
United remain behind Motherwell on goal difference in the standings and Fox lamented the manner of the defeat as his side turn their attentions to the trip to face Hibernian next weekend.
Fox said: “We’re really disappointed we lost the game. I thought we played well for spells in the first half and pushed Rangers — but goals change games and we were disappointed to lose one so soon after the restart. We lose the second so quickly after that, then it becomes very difficult for us.
“You have to give some credit to Rangers. They have some very god players and started well in the second half. You could feel the flow of the game really, really change after the goals. It became difficult.
“There are positives to take from the first half. Our season won’t be defined by Sunday’s result. We have some big games to come and I feel like we’ve made progress.
“But we still have a long way to go and that [result] is probably just a wee reminder of how far we’ve got to go.
“We need to take our medicine - then get back to work because we’ve got a massive game next week.
“That is the job of me, my staff and the players — to take the defeat on the chin, learn from it and then get back to work.
“There were aspects of the first half I was really pleased with but, as I say, the games lasts for 90 minutes and we have lessons to learn from that. We’ll do that and keep pushing.”
