Conor, an ejected sunflower, speaks to Stuff about getting kicked out of a tea party.

A Christchurch man has been taken to hospital with serious injuries after falling through glass before University of Canterbury's annual Tea Party event.

St John spokesman Ian Henderson said a man in his early 20s was "seriously injured" after falling through glass just after 12.15pm on Friday.

The incident happened at a home on Riccarton's Karamu St, and the man was taken to Christchurch Hospital's emergency department in a very serious condition.

IAIN MCGREGOR/FAIRFAX NZ A Canterbury University student tries to get into Tea Party without a ticket.

An ambulance officer told 3 News the man had "almost completely sliced his buttocks off" after falling awkwardly through glass.

The injured man had taken ecstasy and been drinking, 3 News reported.

University of Canterbury (UC) held its annual Tea Party on Friday in celebration of lectures being finished for the year.

Canterbury University students are ready to head to Tea Party in their Wattie's baked bean costumes.

Karamu St was notorious for hosting a street party before the main event and there was police presence there on Friday morning.

Acting Senior Sergeant Ayson Williams said police happened to be in the area at the time of the incident.

"It was at an address where one of those parties were happening," he said.

Williams understood the man had fallen off a roof and through a window, but the circumstances were yet to be confirmed.

The sold out Tea Party and Lincoln University's annual Garden Party were both in full swing by midday as students celebrated the end of the academic year.

The beats were pumping, the costumes rife with colour, and plenty of bodies were squeezing under or over Tea Party's fence.

UC student Paul Eastwood said he saw a couple of successful fence jumps.

"They just lifted the fence and slid under."

Other students were persistent in trying to wriggle their way through the long line to get in.

A student, who only wanted to be known as Conor, said he had tried to get in at least five times but did not have a ticket.

"They are really serious about it this year . . . I haven't been very creative yet I have just kept walking back to the line."

Some students relentlessly negotiated with security while others were almost brought to tears when they were told they were too intoxicated to enter.

Canterbury deployment manager Inspector Peter Cooper said three arrests for disorderly behaviour were made on Riccarton Rd before the event.

"We have noticed there has been a lot of pre-loading before this event . . . intoxications levels are higher than last year."

At least 3000 tickets sold out on October 13, creating desperation among many students.

Some punters took advantage of the ticket drought, with some tickets being sold on Facebook with a starting price of $100. The original cost of a ticket was $39.99 plus a booking fee.

The most notable costumes included a group of sting rays, multiple pandas, three colourful body scrubs, and a crew of Wattie's baked beans.

One of the Wattie's cans, Briana Long, said the group of nine baked beans had been working on their costumes all week.

"We brought sacks they were $3 each. We spent about three days painting them."

Long said most of the group were fourth year students and it was the most organised they had been for Tea Party during their time at Canterbury University.

Canterbury police alcohol harm reduction manager Gordon Spite said overall the behaviour of students had been pretty good during the morning.

A combination of traffic patrols, his staff, neighbourhood policing teams and community officers had been on the look out on Friday, he said.

"Its a challenge . . . they are just kids at the end of the day."

Fire Service southern communications shift manager Tim Reynolds said there was a call to Rountree St in Ilam about 11am because a couch was set alight, but the fire was out on arrival.