By his own high standards, Warner has had a lean series to date, making just one-half century in the first three tests, but the 31-year-old made amends by making a Boxing Day century in front of more than 88,000 spectators, albeit with a slice of good fortune.
He smashed Moeen Ali straight over his head for six in the last over before lunch to go to the interval on 83 but slowed down after the re-start, spending 45 minutes in the 90s and almost coming unstuck on 99 when he chipped a simple catch to Broad at mid-on.
Warner was furious with himself as he started to trudge from the field thinking he had blown his opportunity to reach triple figures only to be given a reprieve when television replays showed the bowler Tom Curran had overstepped the crease for a no-ball.
Given a second chance, the left-handed Warner flicked the next ball he faced square of the wicket for a single to post the 21st test century of his career, and the relief was clear as he leapt into the air and kissed the Australian crest on his helmet.
Warner's joy was short lived however as he departed shortly after, edging a catch to wicketkeeper Jonny Bairstow off James, who joined West Indian Courtney Walsh in fifth place on the all-time wicket takers list with 519.
Warner hit a total of 13 boundaries in his three-hour, 151-ball innings while Bancroft, playing in just his third test, was content to let his senior partner dominate the scoring, managing just two fours in his patient 95-ball knock before he was trapped leg before wicket by Chris Woakes.
Khawaja was also cautious as England's seamers began to tighten the screws by bowling a better line and length.
After piling on more than 100 runs before lunch, Australia managed just 43 in the second session and the buildup of pressure eventually told on Khawaja, who was caught behind by Bairstow off Broad after tea.
Australia went into the match without left-handed fast bowler Mitchell Starc, the leading wicket-taker in the series. Starc was ruled out because of a bruised right foot and replaced by Jackson Bird, who hasn't played a test for 12 months.
England also made one change with Curran selected to make his test debut, replacing Craig Overton, who has a fractured rib.
Curran, 22, has played a one-day international and three Twenty20 matches for England, and was only added to England's Ashes squad when Steve Finn was ruled out at the start of the tour due to injury.
Despite missing his chance to get Warner, Curran bowled 17 tidy overs and conceded 44 runs.