There was only half a unit winning the first prize of last night's Mark Six - taking home HK$66.9 million.

The other half of the jackpot - another HK$66.9 million - will be added to the snowball, boosting the jackpot to HK$80 million to be drawn on Tuesday.

There were also 10 units winning second prize of HK$1.4 million each.

Long queues formed in and outside Jockey Club outlets until nightfall for a pick on the Mark Six, with the jackpot hitting HK$110 million.

With no one winning the first prize in the past eight draws, the jackpot had accumulated to nearly HK$90 million for yesterday's draw.

If there was only one winner for the first prize, the person would have received the highest prize money in Mark Six's history.

At 9.15pm when betting closed, people had wagered more than HK$299 million, the fifth highest turnover in history.

According to the Hong Kong Jockey Club, the highest first prize money was HK$169 million from the draw on May 10, 2016. Two winners shared the prize, each receiving HK$84 million.

The second highest first prize money was HK$164 million from the draw on September 13, 2014. There were also two winners with each getting HK$82 million.

The draw with the highest single winning first prize was on December 10, 2013, when the winner got more than HK$90 million.

All HKJC's off-course betting branches opened at 11am yesterday, one hour earlier than usual.

At lunchtime and after work, hundreds of people hoping to join the ranks of millionaires queued at the betting branch on Stanley Street in Central, where 45 first prize tickets were sold since 1994.

The luckiest betting branch in New Territories is at Tuen Mun Town Plaza, which has sold 38 first prize tickets, and branches at Kwun Tong Plaza and at Tsim Sha Tsui in Hankow Road are the luckiest betting branches in Kowloon, both having sold 36 first prize tickets.

Many people who don't usually buy Mark 6 were also attracted by the enormous amount of prize money, while many people said they would buy homes if they won the first prize, with some saying they would donate part of the winnings.

On Wednesday, a man in Yuen Long jumped into an open nullah from three meters to pick up his lottery ticket, injuring his leg.