Brazilian Casemiro struck late to send Manchester United into the FA Cup quarterfinals with a 1-0 victory over Nottingham Forest as teenagers Jayden Danns and Lewis Koumas inspired Liverpool to a 3-0 win over Southampton on Wednesday.

Chelsea overcame second-tier Leeds United 3-2 thanks to Conor Gallagher's 90th-minute winner, easing the pressure on coach Mauricio Pochettino, and Wolverhampton Wanderers beat Brighton & Hove Albion 1-0 thanks to Mario Lemina's early goal.

United kept alive their last hope of lifting a trophy in a difficult season for the 12-times FA Cup winners when the 32-year-old Casemiro headed in a low bouncing free kick from Bruno Fernandes from close range, setting up an enticing quarterfinal meeting with Liverpool.

United manager Erik Ten Hag and his team held their breath through a lengthy VAR check for offside before the goal was confirmed to the delight of the United fans at the City Ground.

"We scored in the right moment," Ten Hag told the BBC. "Every win is important. This team, what they showed today, that's great. They have to show it every game."

The goal was reminiscent of Mark Robins' famous stooping header against Forest in 1989 which secured victory for United in a crucial FA Cup tie that helped save manager Alex Ferguson's job.

Ten Hag's side are sixth in the Premier League and last weekend's loss to Fulham left their hopes of a top-four finish and Champions League berth hanging by a thread.

"It was an important game for us to win," keeper Andre Onana told the BBC. "I'm happy. We worked hard and this was our reward. At Manchester United you must win. It was a difficult game against a good opponent."

Three days after Liverpool's young side beat Chelsea 1-0 to win the League Cup final, Danns struck twice with his first goals for the senior side and Koumas scored on his first-team debut.

"I couldn't be happier today. Today is the best day of my life," Danns said. "I've watched Liverpool since I was a young boy and to score at the Kop End is more than a dream. I couldn't be happier."

Koumas, the 18-year-old son of former Wales international Jason Koumas, scored just before halftime, receiving a superb pass from Bobby Clark before shooting into the bottom corner via a deflection off Jack Stephens.

Danns, who is also 18, netted his first in the 73rd minute when he dinked the ball over keeper Joe Lumley, and scored again 15 minutes later after pouncing on a loose ball.

With injuries to key players including Mohamed Salah and Darwin Nunez, Liverpool manager Juergen Klopp fielded a young team against Southampton -- 23 spots below them in England's football pyramid.

"It was an incredible game. It was so intense and they ran themselves into the ground, we needed to find a way and we did that," Klopp told ITV.

"The whole situation is horribly difficult," he added about the team's injuries. "Any positive mood around the changing room and training room, we accept we're in a difficult moment and try and find solutions. It's great to be in the quarter-finals and we don't take these things for granted."

CHELSEA CHANCE

For Chelsea, struggling in mid-table in the league, the FA Cup is their last realistic chance of silverware.

The Premier League side were shocked in the eighth minute when Leeds took the lead after a defensive mix-up playing out from a goal kick allowed Mateo Joseph to score his first senior goal.

Chelsea replied with two goals from flowing moves in the 15th and 37th minutes and fine finishes by Senegal's Nicolas Jackson and Ukrainian Mykhailo Mudryk.

Leeds upped the intensity in the second half and were rewarded in the 59th minute as a free header from the unmarked Joseph flew past Chelsea keeper Robert Sanchez.

Pochettino brought on Gallagher and Ben Chilwell as well as top scorer Cole Palmer in the second half and the move paid off. With extra time looming, Gallagher latched on to a pass from Argentine midfielder Enzo Fernandez before shooting home to take Chelsea into the last eight.

Pochettino called the win a "big relief".

"It is difficult because of the expectations," he told ITV. "The expectation is massive because we are Chelsea but this team needs to build and build the confidence. The unity is starting to grow, it's not magic, you can't just create it."

Liverpool travel to Old Trafford to face Manchester United over the weekend of March 16, champions Manchester City host Newcastle United, Chelsea play Leicester City and Wolves take on Coventry City.