Just days after a stunning fade-out cost them victory in game one in Melbourne, the Hawks again looked gone when trailing by three with 25 seconds left.

It saw Justin Tatum burn his final timeout. A composed Tyler Harvey spurned a Hail Mary shot at an equaliser and settled for a quick two to draw within one and force Dean Vickerman to use his final timeout with 13 seconds left.

It looked worst-case-scenario when United found Chris Goulding with the in-bound, only for arguably the coolest character in the NBL to inexplicably go 1-2 from the line.

With no timeouts remaining the Hawks went up the floor and found Gary Clark, whose lay-up rimmed out only for cult hero Will Hickey to swoop with the offensive board and put-back with less than a second on the clock.

It allowed the Hawks to well and truly turn the overtime tables, riding the momentum to outscore United 16-11 in the extra time to send the series back to Melbourne on Wednesday.

Star import Clark showed why Hawks fans so desperately want him to stick around beyond this season with a monster 31 points, 16 rebounds and three assists.

In a sign of just how far he's progressed under Tatum, Hickey proved the chief support act with a career-best 18 points, five rebounds, three assists and three steals - as well as the put-back that sent the game long.

Skippers Tyler Harvey and Sam Froling both overcame slow starts to compile 23 and 19 points respectively, the latter also adding 13 rebounds and four assists.

It will see the Hawks looking to inflict on United what no side has managed all season - two consecutive losses - to book a grand final berth.

It's highly unlikely the Hawks will get another opportunity to lead by 16 with seven minutes left, but a game three on Wednesday is now a win-or-go-home prospect for both sides.

Parking the disappointment of last week's stunning fade-out to bounce back in quick time showed all the man-management qualities that had Tatum in the running for NBL Coach of the Year just 19 games into his professional career.

He now has the opportunity to pull off an even more stunning boil-over against the man who claimed that award in Vickerman on Wednesday.

"I think [I've aged] a decade, for sure," birthday boy Tatum said post-game.

"Every time that we've played Melbourne we have been up in double digits and left the lead out there and they took the game from us.

"I just kept reminding the guys that we won 90 per cent of that game this past Wednesday, that this is a beatable team.

"We have to play our game for 40 minutes and, once we do that, we can figure out how to win it. We got it in the same situation I felt that we were in Melbourne, not as many points of deficit, but they went on a 6 or 8-0 run while we were up.

"I just reminded the guys just to keep fighting, that we've been through this before, and stick with what's been working for us. We figured it out."

It sounds almost boring to sing the big man's praises, but there's not much else to do following his huge showing - in particular in the early stages.

The Hawks looked to have missed the jump early, but Clark kept things ticking with 18 points at 6-8, and seven rebounds at the half.

The effort kept the Hawks in the contest long enough for others to find their groove.

"GC was unbelievable today, he was we've been seeing all season besides a game or two," Tatum said.

"His impact early was just much needed. When GC's locked in like that and we see that he's going, that's who we feed off.

"He's a true competitor and I'm glad some shots started to go down early for him because he does get a lot of attention from the other team

"It was good to see GC do great on both ends with the scoring the points and the rebounds, 16 rebounds was unbelievable out of him."

If there's one story that can possibly rival that of Tatum's itself this season it is the Hawks faithful's newest cult figure Hickey.

The livewire has gone from riding the pine to being an indispensable part of Tatum's starting - and crucially closing - unit.

His ability at both ends of the floor was again on show as he dogged United star Matthew Dellevadova down the stretch and dropped his own clutch free-throws.

Un-signed beyond this season, the club's front office might want to jump on the Hawks' fan favourite before the present season is out.

"I'm not going to lie, once Gary got the ball up it was just instinct," Hickey said of his game-tying shot.

"I got the ball, took my time and made the lay-up. As we were walking back to the bench I said to a few of the boys 'did that count?'

"I wasn't confident in it, but once I sort of looked up and saw it, it was just a knack to get to the ball. Once Gary put it up, I just got around the rim and hoped for the best."

Skippers Harvey and Froling had 11 points between them at the half, but combined for 16 with the game in the balance in a third term that saw 13 lead changes.

Harvey had nine of his 24 points after three-quarter-time, including the key basket with 13 seconds left and another from mid-range for a five-point lead with 33 seconds left in overtime. It proved the dagger basket.

"We wanted a three if we had it, but we felt that we had enough time that we could go for a quick two," Tatum said.

"I'm glad Tyler and GC made a quick decision and that was Tyler's little patent shot where he goes down for the floater.

"We knew we had time after that and we were going to foul and luckily we got one missed free throw out of them to be able to come down and tie it up at the end.

"Our composure towards the end and the fourth quarter and going to overtime was exceptional."