Richard Agar suffered disappointment on his KC Stadium return as Wakefield's late revival failed to beat Hull FC.
With both sides scoring two tries, it was second row Danny Tickle's kicking that proved the difference.
Hull led 8-0 at the break after Kirk Yeaman's try, Tickle adding a penalty to his conversion.
Will Sharp appeared to have wrapped it up, only for Wakefield to respond with two tries in the last 10 minutes from Ben Cockayne and Kyle Wood.
Agar was sacked by new Hull owner Adam Pearson at the end of last season following seven years at the club, half of which time he spent as head coach.
But his successor, Australian Peter Gentle, was the one celebrating as Hull maintained their unbeaten home record with a solid display in foul weather conditions.
For Agar, more pressing matters than beating his former side will be his focus as Wakefield search for a first win since beating Super League newcomers Widnes in the opening game of the season.
Torrential rain which soon turned to snow meant conditions were atrocious at the KC Stadium, but both sides creditably kept errors to a minimum.
Hull were in control and heading for a first clean sheet in six years after Sharp had doubled their try haul just past the hour following Yeaman's 18th minute opener.
But Agar's Wildcats still had some bite left in them, staging a rousing comeback to almost snatch the points.
First, former Hull KR favourite Cockayne took pleasure in spoiling the party after a mistake by Hull full-back Wade McKinnon.
And, with five minutes remaining, Wood scored after another scramble in front of the Hull posts.
A nervy finish ensued, but the hosts were able to hang on for a win that, with 10 minutes to go, had never looked in doubt.
VIEW FROM THE DRESSING ROOM
Hull coach Peter Gentle:
"We were in control for a long time and, with the field position we had, we should have been further ahead. But, with the poor weather conditions, the game was messy and we were glad to win it in the end. We nearly threw it though.
"It was tough because you train all week to play a certain brand of rugby and then with the weather you have to change that somewhat and we were rehashing things in the dressing room before the game. We got the points though so we are happy with that.
"We had more than enough field position and opportunities to put the game to bed and we should have done that. We are still struggling with how we want to play and the guys were torn with how we have practised all week and how we had to play in this game because of the weather."
Wakefield coach Richard Agar:
"I thought we were tremendously courageous and had to withstand a lot defensively, but our defence really held up.
"We finished the stronger side and the players felt if we had another two or three minutes we would have gone on and won the game. Our performance showed a lot about our character.
"Hull played with more energy but to come back as we did, we will take a lot out of that performance from a defensive point of view and a character standpoint because we had them on the ropes at the end and they were hanging on for a victory."
Hull: McKinnon; Sharp, Martin, Yeaman, T Briscoe; Horne, Seymour; O'Meley, Houghton, Lynch, Manu, Tickle, Aspinwall.
Replacements: Moa, Ellis, Whiting, O'Carroll.
Wakefield: Mathers; Fox, Collis, Mellars, Cockayne; John, Smith; Raleigh, Aiton, Southern, Kirmond, Lauitiiti, Washbrook.
Replacements: Wood, Johnson, Wilkes, Walshaw.
Referee: Steve Ganson (St Helens).