The 19-year-old was a surprising name on Dean Smith's team-sheet but the young left back demonstrated his prowess until he was forced off with a calf injury.
He won the ball off Jazz Richards in the build up to the first goal inside the first five minutes.
Just 35 minutes later, Field was taking more plaudits after his corner was slammed home by Scott Hogan to make it 3-0.
Although his afternoon came to a premature end, the youngster impressed with virtually everything he did.
Speaking about his debut, Field said: “It's stuff dreams are made of. You can never imagine getting an assist and having a hand in another goal.
Video Gallery: See Brentford fans enjoy their 3-0 win over Fulham
“I found out at the end of the session yesterday. I didn't have much time to prepare and the crowd were behind me from the start.”
Bidwell was seen as the Bees' one and only option at left back but now it is plain to see that he has a young player capable of stepping into his large shoes.
And Field is promising to get even better as he gains in experience.
He added: “I showed a lot but I've got more to my game. My game is attacking – it's not really defending but I can defend.
“As it was a west London derby I don't want to bomb forward and get exposed. I tried to keep things as simple as possible.”
Field, assuming he shakes off his calf injury, could make a second start for Brentford if Bidwell's hamstring complaint doesn't go away.
But, whether he plays or not, the young left back is determined to make his captain and role model battle for the shirt.
He explained: “We don't know what Jake is going to be like next week. If he's fit then I'm happy to wait until pre-season.
“I don't need to be any rush. Jake Bidwell is a great player and he's so consistent. In pre-season I want to push him. We'll push each other and make each other better.
“I've been waiting for the opportunity but I'm glad I've had a chance and the fans can see they've got a left back in the U21s and the club don't need to buy one.
“Jake is one of the best role models you can have in your position. He came and sat right by me and told me the fans won't phase you and, if anything, make you play better. He said get your first touch, play a simple first five minutes and see how it goes.”
Field's first involvement for Brentford came in side that won the Milk Cup in 2012, beating Liverpool and Everton on their way to glory.
“I was playing Sunday league football aged 14 before joining the club,” he explained. “I was 15 so started at the Under-16s. I went to the Milk Cup where we won that – it wasn't a bad debut.
“I've got to thank the coaches I've here form U16 to U17. I have had the privilege of working with the best coaches in England and they've helped my game myself.
“I think my tactical game has come on the most – in park football it's not tactical. If you're quick you're good at that level. I think my tactical game has come on a bit. The difference is crazy.
“I've got loads more to do. I think my most important thing to develop is my positioning. I used to be a winger before making the transition.”