WINDSOR, Ont. -- The Saint John Sea Dogs' season was on the line and they needed more from Callum Booth after a blow out by the Erie Otters only 24 hours earlier.

Booth delivered.

The 20-year-old goaltender made 31 saves and Joe Veleno had two goals and an assist as Saint John downed the Seattle Thunderbirds 7-0 on Tuesday to advance to the Memorial Cup semifinal.

Only a night earlier Booth gave up five goals on 14 shots and found himself on the bench watching his team drop a 12-5 decision against the Erie Otters. He entered Tuesday's tilt with a 5.46 goals-against average and a .784 save percentage in two tournament starts.

"Yesterday was a really hard game personally," said Booth. "It's definitely not easy, I wasn't up to my standard I hold myself to.

"It's easy to say you just forget about it, but there's always something hanging in your mind. So the fact my defenceman let me see the puck and get a feel for it helped."

Saint John will face the loser of the last round-robin game between the host Windsor Spitfires (2-0) and the Ontario Hockey League champion Otters (2-0). The winner of the all-OHL matchup earns a direct route to the championship game on Sunday.

The Sea Dogs opened the Memorial Cup with a 3-2 loss to Windsor before their drubbing against Erie.

"They're two big challenges and they showed us that," said Booth. "We did struggle, but we showed tonight we can compete."

The season is over for the Western Hockey League champion Thunderbirds after going 0-3 at the tournament. They scored just three goals and gave up 18.

"You're gonna have your ups and downs in life and that's part of it," said Seattle coach Steve Konowalchuk. "Understand what you're feeling, it's not good, but it can make you better."

Chase Stewart, Mathieu Joseph, Spencer Smallman, Cole Reginato and Bokondji Imama supplied the rest of the offence for the Quebec Major Junior Hockey League champion Sea Dogs (1-2). Imama tacked on two assists for a three-point outing.

Seattle's Carl Stankowski gave up four goals on 14 shots before getting yanked for the second straight game of the tournament for Rylan Toth, who made 11 saves in relief.

Some 4-on-4 hockey led to Booth having to bail out his team, stopping Scott Eansor on a breakaway after a turnover by Veleno just outside the Saint John blue line to keep it scoreless after 20 minutes.

Veleno put his team on the board first, 1:14 into the second period, snapping a shot from between the top of the circles low glove side on Stankowski after Seattle turned the puck over on the sideboards.

"It could have been anyone," Veleno said about scoring first. "It led to a couple more, we started getting momentum."

Thunderbirds captain Mathew Barzal blocked a shot with the back of his left leg that left him slow to get up, but he was out for his next shift and nearly scored with a wrist shot Booth had to kick out.

Seattle had the better scoring chances in the first half of the second, but Booth was perfect on the 20 shots he faced in the game's first 30 minutes.

Booth's play proved to be big as it allowed Saint John to take a 4-0 lead with three goals in a 53-second span.

"Callum's been good for us all year, tonight he was great," said Veleno.

Stewart scored on a pass from Jakub Zboril at 14:04, and Joseph snapped it blocker side on Stankowski before the P.A. announcer had a chance to call Stewart's goal just 15 seconds later.

Smallman ended Stankowski's night with 4:03 to play in the second, putting a backhand past the helpless keeper.

"The wheels fell off real quick when they scored that second goal," said Konowalchuk.

The goalie change didn't spark Seattle, though, as Reginato and Imama added goals only 44 seconds apart to make it 6-0 through two periods.

"It's fun as a goalie when your team can score six goals in a period, takes some pressure off," said Booth.

Just after killing off a Sea Dogs power play, Veleno made it 7-0 seven minutes into the third with he second of the night.

Saint John will have Thursday off, with the semifinal going Friday.

"Game like this gave us a lot of confidence, semifinals coming up and we're going to do everything we can for that game," said Veleno.

We know we deserve to be here."