All the pre-match focus had been on the England forward's eagerly-awaited return to Super League after a four-year stint in Australia but he was sensationally ruled out after damaging an ankle in the warm-up.
Richard Whiting had to take Ellis' second row spot and Chris Green was promoted from 18th man to the bench. However, inspired by long-serving half-backs Danny McGuire and Rob Burrow, the champions wore down the visitors' resistance to score five tries in the last 25 minutes and run out comfortable winners.
Leeds also lost one of their newcomers, Australian winger Joe Vickery, with an ankle injury but it could not take the gloss off a polished performance by the champions, for whom skipper Kevin Sinfield scored the points he needed to climb to eighth in the league's all-time list of scorers.
Engage Super League
Dixon joins Salford
Hull had dominated the opening exchanges, helped by a couple of penalties conceded by Leeds forward Ryan Bailey. However, both defences looked superbly drilled and it was a blunder by second rower Ben Galea that resulted in the game's first try.
It came, on 15 minutes, when Galea's cold hands fumbled McGuire's grubber kick on his own line and Sinfield got his hand to the ball. The conversion took Sinfield ahead of Leeds legend Lewis Jones in the all-time list of scorers but the score failed to produce the anticipated points spree from the champions.
Leeds lost debutant winger Joe Vickery with an ankle injury after 28 minutes and Hull drew level shortly afterwards when replacement Aaron Heremaia's lightning break set up the position for Joe Westerman to get centre Joe Arundel over for a try.
Holdsworth's angled conversion levelled the scores and it remained at 6-6 until the 56th-minute. Leeds ought to have made more of a clinical break by the ever-dangerous McGuire and they would have scored had Burrow been able to take an awkward pass by winger Ryan Hall.
Debutant centre Joel Moon took Sinfield's long pass and, despite slipping on the greasy turf, managed to nip through a gap to touch down. Sinfield's second goal made it 12-6 and he was again on target shortly afterwards when Jamie Peacock took a pass from his skipper and sidestepped his way past full-back Shannon McDonnell for a rare try.
McGuire got back rower Chris Clarkson galloping 30 metres for a try before racing over himself for a deserved score and Hall bumped off the challenge of Arundel to romp over for Leeds' sixth try, to which Sinfield added a sixth goal.
In the night's other game, Sam Tomkins underlined his status as Super League's poster boy by launching the new season with a hat-trick in an emphatic 42-0 Wigan win at Salford.
The Warriors' star full-back ran in three of his side's eight tries to puncture a party atmosphere at the Salford City Stadium sparked by the Reds' recent takeover. Five-goal Pat Richards, Matty Smith, Josh Charnley, Iain Thornley and Liam Farrell also touched down for Wigan.
The change of mood at Salford after their winter of turmoil was evident before kick-off as new owner Dr Marwan Koukash was introduced to the crowd. And while Koukash's arrival may have come too late to infuse Phil Veivers' squad with much extra quality, a strong collective spirit was initially evident.
Jack Murphy, who joined the Reds on loan from Wigan this week, made a positive start against his parent club as he raced across to gather a loose ball as Charnley threatened. Salford held firm for a spell but were eventually caught out after 13 minutes as Wigan debutant Blake Green sent Farrell through a gap.
Farrell dummied and continued his run before handing Tomkins the simple task of touching down. Salford rallied as highly rated French youngster Theo Fages, partnering veteran Ryan McGoldrick at half-back, showed promising signs on debut with a 40-20 kick.
Wigan extended their advantage 12 minutes before the interval as Smith sidestepped through a gap and barged through the challenge of Murphy on the goalline to score. There was further anguish for Murphy just three minutes later as he dropped a long Wigan kick into touch in dangerous territory.
Wigan worked the ball excellently from the resulting scrum and Charnley found room out wide from a Tomkins pass to beat Jodie Broughton and score. The quickfire double broke the challenge of Salford and the best they could muster in response was a move which took Murphy close to the line and gave McGoldrick the chance to kick.
Tomkins cleared the danger and although Sean O'Loughlin was penalised for a high tackle on Fages, Wigan were not worried. Even after Gil Dudson was sin-binned early in the second half for interference - referee James Child having warned the team before the break - Salford rarely threatened.
Wigan claimed their fourth try when Sam Powell's grubber kick was seized by Thornley. The Reds were undone again on the hour as Tomkins broke and Richards cut between two tacklers to cross in the corner.
Another try swiftly followed as Thornley found Richards and Farrell ran through to score from his pass. Tomkins had a trademark individual effort which took him behind the posts with just over 12 minutes remaining. He then completed his treble before the final hooter as Green outfoxed the defence to send the full-back through the posts.
Engage Super League
Wakefield win fifth straight with late drop goal
Engage Super League
Broncos hammer weakened Warrington