Green Party health spokesman Kevin Hague admitted there had been a backlash from some within the party when the Greens opposed the bill on the first occasion.
"Some people thought that because it's popular that actually we should be supporting it," he said.
His party had changed its mind after Mr Seymour had agreed to make improvements to the bill.
The Greens supported the bill's first reading in the expectation those improvements would be made, despite the legislation being unchanged when it was tabled in the House.
Mr Hague told Parliament that special licenses that can currently be granted under the law were designed precisely for events like the World Cup, but it was apparent that police in some areas were saying that fixtures did not qualify.
"What we need is a review of how Parliament's intentions around special licenses have been implemented. But we don't have time right now."
Mr Seymour said he considered some of the Green proposals, such as restricting pubs which had previously breached licensing conditions, but said the party's other proposals were unworkable.
After the Act bill was shot down by the Greens on Tuesday, the Government began drafting its own legislation.
That work would now be scrapped, and the Government planned to propose changes at the committee stage.National wants the law change to apply only to All Black games and knockout matches - a total of 12 matches.
Mr Seymour said only broadcasting All Black matches was "deeply unfair" to New Zealand's many ethnicities and he wanted it to apply to all 48 games.
Labour and New Zealand First are lobbying for the legislation to be widened to cover all major sports events such as the Netball World Cup and the Olympics.
Labour leader Andrew Little said pay TV was too expensive for many New Zealanders and their only opportunity to watch the country on the world stage was in a public place.
Mr Key said he wouldn't rule out a broader bill which covered other events.
"If there was an event that was significant enough that we thought was in a time zone that warranted it, we'd look at it."