Durham pace-man Onions, who has not played Test cricket for two-and-a-half years due to career threatening back injuries, was part of a three-man pace attack, which reduced West Indies to 280-8 at stumps.
“There were a few nerves, that’s only natural, but I loved it today,” he told Sky Sports.
“It was hard work but I really enjoyed it. It’s been over two years since I played and I’m delighted that I came back from lot of injury troubles.
“The lads today put in lot of hard work and I’m proud to be part of it.
“It was a tough, six or seven months I spent coming back, not knowing if I would ever play again which was the tough part. But everyone at the ECB has been fantastic.
“It’s always nice playing for England, but when you’ve gone through that, playing for England is even more special.”
Captain Andrew Strauss won the toss and inserted the tourists, who had made four changes to the side that were comprehensively beaten at Trent Bridge to trail 2-0 in the series.
Shivnarine Chanderpaul was not in the Caribbean Islanders’ side after picking up a side strain and will now, at the age of 37, have no doubt played his final Test on England shores.
However, despite not having the world number one batsman in their ranks, the Caribbean side started strongly and were 85-1 by lunch; Yorkshire’s Tim Bresnan picking up the solitary wicket of Kieran Powell, caught by Graeme Swann at slip.
With the first two days of this Test washed out both Steven Finn and Onions were finally given the chance to prove themselves as Stuart Broad dropped out of the side due to a cold. Strike bowler James Anderson had been left out of the squad last week to give the Lancashire quickie some rest, with a long summer of cricket ahead of the Three Lions.
After lunch the West Indies fragile batting order began to crumble and the tourists were 164-5 at tea.
Finn picked up a brace, removing Darren Bravo and skipper Darren Sammy but was unlucky not to remove opener Adrian Barath, who was twice dropped before Onions snaffled him for 41.
Marlon Samuels was once again in fine form with the bat making a fine 76, taking him to 386 runs in just his fifth innings this series. He shared a sixth wicket partnership of 56 with wicketkeeper Denesh Ramdin, who finished the day on 60 not out.
MORE: The latest football news
MORE: The latest tennis news
BIOGRAPHY: Nabil Fekir
BIOGRAPHY: Sokratis Papastathopoulos