For the majority of their semi-final clash against Melbourne United on Thursday night it looked for all money that Illawarra would return to a packed WIN Entertainment Centre on Sunday just one win away from securing a grand final berth.

Instead a horror late fade saw them squander a 16-point lead to go down 115-106 in overtime to Melbourne United.

So instead of playing for a grand final berth the Hawks will need to win just to keep their season alive and send the series to a deciding game three in Melbourne next Wednesday, March 13.

The positive for Justin Tatum and his team is that the Hawks have performed well in Wollongong when their backs have been against the wall.

Illawarra needed to win their final home game of the season against the Perth Wildcats to secure a top-six finish and they did just that, securing a third straight win over the Wildcats in the process.

On Monday this week the Hawks returned to the WEC and downed the New Zealand Breakers in their do-or-die finals clash.

Though that 88-85 play-in victory masked the Hawks inability to hold on to big leads.

Illawarra found a way to beat the Breakers, thanks in large parts to Justin Robinson, who iced the win for the Hawks who led by as much as 15 early on but found themselves chasing the game after Breakers took the lead in the fourth.

Fortunately Robinson went 14-14 from the line, including a cool six of six inside the final 29 seconds to first re-take the lead, and then hold it to the final buzzer.

There were no such heroics unfortunately against United as the championship favourites went on a 23-7 run with seven minutes left to play to come back from 16 points down to tie the scores and send the game into overtime.

Melbourne then went 15-6 in overtime to seal a 115-106 win which put them in the box seat to sweep the Hawks in Wollongong.

While the late fade out was mainly self-inflicted, Hawks coach Tatum had some backers when he argued against some highly questionable officiating that saw key calls go against the Hawks late in the piece.

Tatum acknowledged Melbourne's superiority in the clutch but felt Illawarra copped a raw deal from the officials late in the match.

"Them being at home, turning up that tempo a little bit, that pressure and their experience ... they got away from us," he said.

"Also other people have got to do their job and call the obvious things and don't let them play into their hands.

"We were fighting other things out there as well."

He also touched on how things went so bad for the Hawks after Illawarra produced arguably their best three and half quarters under Tatum.

"Our tempo wasn't at the same pace that helped us get that 16-point lead," he said.

"This one is on me. My team understands that they've got to make sure that they find a way to pull the game out.

"You can't have a 17-point lead with any team and then allow them to come back, but I take this one on the chin as far as the preparation, the experience and getting them through this one.

"We'll be ready for the next one."

Illawarra Hawks v Melbourne United game two at the WEC on Sunday tips-off at 3pm.