Hull turned on the style against struggling Widnes to claim a third successive win that lifts them up to second place in the Betfred Super League table.
Match stats
Hull tries: Kelly (8,52), Fonua (32), Houghton (47), Shaul (50)
Conversions/penalties: Sneyd (8,32,39,48,51,54)
Leigh tries: Heremaia (4), White (71)
Conversions/penalties: White (4,72)
Match report
It took Lee Radford's men 31 minutes to take the lead at the KCOM Stadium but they cut loose early in the second half with three tries in a six-minute spell and eventually ran out 32-12 winners to leave the Vikings still looking for their first win of the season.
Stand-off Albert Kelly scored two tries for the third successive match as Hull, boosted by the return of inspirational captain Gareth Ellis, show signs of hitting their straps.
Widnes coach Denis Betts left out full-back Rhys Hanbury, with Corey Thompson doing a fine job at the back after being switched from the wing, while youngster James Chapelhow stepped up in the absence of three specialist props but their deficiencies were exposed in the second half.
The visitors took the lead after only three minutes when former Hull half-back or hooker Aaron Heremaia, making a rare start in the absence of injured duo Joe Mellor and Tom Gilmore, took a pass from Lloyd White to dart through a gap for the opening try.
White's conversion made it 6-0 but the lead lasted just three minutes as winger Mahe Fonua collected Marc Sneyd's high kick and passed out of the tackle to get the supporting Kelly over for a try that Sneyd goaled.
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The scoring dried up as defences tightened, with stand-off Danny Craven going close for the visitors and Hull failing to make the most of a clean break from substitute prop Chris Green.
Fonua (pictured) eventually broke the deadlock nine minutes before half-time when he accepted Kelly's cut-out pass to produce a strong finish at the corner and put his side in front for the first time.
Sneyd kicked the touchline conversion and added a penalty on the stroke of half-time to stretch the lead to 14-6 but, after a tight first half, it was virtually one-way traffic after the break.
Hooker Danny Houghton touched down a Sneyd kick in a move practised to perfection on the training park, second rower Mark Minichiello smashed a hole in the Widnes defence to get full-back Jamie Shaul over and Kelly charged over from 20 metres out for his second try.
The accurate Sneyd maintained his perfect record with the boot to extend the lead to 32-6 after only 52 minutes.
But Widnes rallied in the final quarter and scored the only further points 10 minutes from the end when Chris Houston's kick on the last tackle ricocheted into the arms of White, who touched down for the try and added the goal.
Match reaction
Hull coach Lee Radford on what the win means: "First and foremost I'm pleased with the result. How we started the second half went a long way towards dictating the scoreline. I'm pleased with the way we went about our business.
"There was some fluency in what we did, which I said would come. It sets us up nicely for the fixture next week. Wigan at Wigan is a tough fixture and it's one we're looking forward to."
On the return of Gareth Ellis and the form of Albert Kelly: "It was a really tidy performance from Alby - for a small bloke he plays physical. He looks like he's enjoying himself and he's added a bit to us offensively.
"It's always good to see Gaz back in the jersey, he does what he always does, he led from the front."
Widnes coach Denis Betts on still looking for a first win: "We keep giving sides 18 points by rolling over in patches in the game. We are making it easy for sides. We were up against a side running pretty hot with threats from all over the field but I felt we handled them well for big patches of the game.
"We went toe to toe with them in the first half, which shows we're not far off but then we hit a patch and look like a side that looks like it doesn't know what it's doing. We were defending our line well but then we give penalties away and it takes energy out of our attack.
"The energy we wasted in conceding penalties is causing us some problems. I feel we've got two or three players under-performing, we're lacking that cutting edge to break open a game."