Hussain arrived at the Old Calder Highway from Williamstown CYMS as a highly-touted opening batsman who peaked as a first-class cricketer with Lahore in his homeland Pakistan.

But the summer has been one of frustration for Hussain - until now.

The 32-year-old was relegated to first drop in the batting order and even batted as low as No.6 in a recent game against Tullamarine to have just 193 runs at 16.1 before the weekend.

"He came to the club highly recommended," Blues coach Nigel Freebairn said.

"He was originally recruited as an opening batsman but due to other circumstances we've batted him at three."

Having failed to bring up a half-century in his first 13 disappointing digs with the Blues, Hussain broke the floodgates open on Saturday with a stunning 122 in his side's imposing total of 7-279 declared off 74 overs.

Donning a distinctive floppy hat when he brought up the milestone, Hussain turned his season on its head with an individual performance that was so good that Freebairn declared the opener's role his to lose.

"It was one of the finest knocks in recent memory at Keilor," Freebairn said.

"I told him there was no pressure and to spend time in the middle and he batted 68 overs.

"He went out sacrificing himself for the team [in search of quick runs] at the end.

"It was a breakthrough innings and that openers' spot is his for the rest of the season now."

Hussain featured in a 216-run stand with his captain Danny Law.

Law made a delightful 113 - his second ton of the summer since also crossing from CYs.

Law's main contribution was guiding the way for aggressor Hussain when it appeared he was floundering in the intense heat.

"It was a wonderful partnership," Freebairn said.

"It was a hot day and whenever Ali looked to be tiring Danny would go and tell him to get focused and back on track.

"There were animated celebrations when the two brought their tons up.

"They appreciate that we'd had two ordinary games and for us to consolidate with two centuries was great."

The Blues decided they had plenty of runs on the board to defend and left themselves with five overs to rip into the Bombers' top order.

It worked a treat for the hosts with speedster Dan Schuppan getting a breakthrough and leaving the tourists on a shaky 1-3 at stumps.

"Two hundred and eighty is a massive score at Keilor," Freebairn said.

"We're confident of defending it."