The former Hearts player was the centre of attention after his introduction on to the pitch and the Hibs fans reacted furiously to some later gesturing from the Czech attacker, who had what looked like a perfectly good late goal chalked off by the linesman for offside.
"We said to them to not get involved in anything." Fenlon said "It's about playing football matches and winning games. The best answer for anybody is to go and win the game."
The match represents an incredible turnaround for Hibs - it is the first time they have played United since being badly beaten 3-0 on the opening day of the season.
"I certainly didn't think after Tannadice that we'd be sitting here, today, top of the league." Fenlon said.
"That is great credit to the players. They knew they didn't work hard that day, but they've rolled their sleeves up and worked hard to get better.
"I thought it was a complete performance today. We were superb in the first half and in the second half we had to defend, football is about doing both."
"It shows we've come a long way."