A Olympics hockey referee got her face slashed during the USA-Canada match and needed stitches but returned to finish the game

• A referee got escorted from the ice after suffering a bloodied mouth from a wayward stick.
• It all went down during a grudge match between old rivals Canada and USA.

A referee got her face slashed during the USA-Canada hockey match Monday at the Winter Olympics, and needed two stitches to recover.

The United States played well at the Wukesong Arena in Beijing but left the ice having lost 4-2 in the preliminary round grudge match.

The battle between the old rivals was not the only headline to emerge from the game, as official Cianna Lieffers had to receive medical attention because of an injury suffered midway through the action.

"Official coming off the ice bleeding," Premier Hockey Federation broadcaster Erica L. Ayala tweeted at the time. "Wild how visors don't protect your mouth."

Team USA star Amanda Kessel was skating past Lieffers, looking in another direction, and her wayward stick ended up causing the damage to the ref's mouth.

She grimaced in pain and held her face before Canada's training team escorted her from the ice.

Lieffers signaled to the cameras, Ayala reported, as if to say "no pictures."

Despite her bloodied mouth, Lieffers returned to the rink so she could finish officiating the match — which Canada won, having come back from 2-1 down to win 4-2.

The Canadians took fewer shots than the Americans and were far more efficient in front of goal.

"For us, we really want to focus on quality chances over quantity," Sarah Nurse, a forward, said, according to New York Times. "I know that we've had a lot of shots this tournament, as well, but I think we have a big focus on getting Grade A scoring chances."

Nurse then said a key reason for keeping the Americans at bay was their focus on attempting shots from distance. "We had a stellar goaltender, and so if you're going to be shooting from the outside, you're not going to score on her."

Canada and USA both progress to the quarterfinals

The result ensured Canada topped Group A with a perfect record of four wins from four matches, yielding 12 points.

USA trailed its rival by three points, finishing in second place with three wins and one loss from four matches.

Both nations progress to the quarterfinals which begin later this week.

Canada plays Sweden for the right to advance to the semis, while the USA take on Czech Republic.

All matches take place February 11 to February 12.