|Betfred Super League|
|Castleford Tigers (16) 42|
|Tries: Eden, Laulu-Togaga'e, Cook, Trueman 2, Sene-Lefao 2 Goals: Ellis 7|
|Leeds Rhinos (10) 10|
|Tries: Briscoe 2 Goals: Sutcliffe|
Kevin Sinfield suffered a heavy defeat by West Yorkshire rivals Castleford in his first game in charge of struggling Super League champions Leeds.
The former Rhinos captain, who replaced Brian McDermott on Friday, oversaw Leeds' eighth straight league defeat, which left them ninth in the table.
Tom Briscoe twice put Leeds ahead, but Castleford led 16-10 at the break.
Teenager Jake Trueman then scored two tries and helped Jesse Sene-Lefao grab a double to inspire Tigers to victory.
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The win lifted Daryl Powell's Castleford side up to third in the table.
Leeds ninth are two points behind eighth-placed Huddersfield Giants with three regular-season matches remaining.
Tries from the fit-again Greg Eden, Quentin Laulu-Togaga'e and Matt Cook were enough to edge the hosts ahead in a fast-paced, high-quality and draining first half.
After the interval, Trueman wreaked havoc on a Rhinos side fighting to avoid playing for Super League survival via the Qualifiers.
Losing captain Stevie Ward to injury early in the second half robbed the visitors of one of their biggest influences and left Sinfield short of an on-pitch leader in a increasingly trying situation.
'Got the full picture'
Sinfield, who served Leeds for 18 years as a player before retiring as a treble winner in 2015, said he now appreciated the scale of the task.
"I have enjoyed the last two days," he said. "I didn't enjoy the last 80 minutes if I'm honest but I've got the full picture now. I know exactly where we're at.
"I knew it was a big job, otherwise Brian would probably still be here.
"Previously I've been looking at it as an outsider, now I'm in the middle and I'm right in there with them.
"My focus is now Wakefield [on Friday]. I don't want the lads looking at the league table - I certainly won't be looking at it."
Defeat marked the end of a week of upheaval at Headingley, which began with McDermott being sacked after eight years in charge and led to former captain Sinfield being named as his successor on Friday.
While his coaching debut came at short notice and against a fierce near neighbour - who Leeds beat in last year's Grand Final - the 37-year-old at least got the ideal start as Briscoe grabbed the game's first points in the third minute.
Eden, Super League's top try-scorer last season, then quickly marked his return from a hamstring injury with Tigers' response, and Laulu-Togaga'e and Cook sandwiched Briscoe's second score.
Trueman began to impose himself on proceedings before half-time and the teenage half-back went on to star after the interval as Castleford pulled clear.
'Making the story about Tigers'
Tigers coach Powell had ruled himself out as a contender to succeed McDermott, prior to Sinfield's appointment.
He said it took "a lot of composure" in "awkward" and hot conditions to fight back to beat Leeds.
"Leading up to game it was all about Leeds and what happened there," Powell said.
"We had to focus on us and make sure the story tomorrow was about us.
"It took a lot of composure from the boys to get us out of it but I thought in the second half we were very good."
Castleford Tigers: Laulu-Togaga'e; Clare, Webster, Shenton, Eden; Ellis, Trueman; Watts, McShane, Sene-Lefao, Moors, Millington, Milner.
Replacements: Holmes, Massey, Cook, Clark.
Leeds Rhinos: Golding; T Briscoe, L Sutcliffe, Moon, Hall; Lilley, Myler; Oledzki, Parcell, Singleton, Ward, Ferres, Cuthbertson.
Replacements: Walters, Walker, Mullally, Delaney.
Referee: Liam Moore.