Russell Martin’s half-time hairdryer set up Southampton’s second-half surge to send them to a 3-0 FA Cup replay win over Watford and a fifth-round clash with Liverpool.

Saints were dismal in the first half before Sekou Mara bagged a brace of well-hit strikes and Che Adams secured a 24th game unbeaten for the Championship promotion hunters.

“I wasn’t happy with the first half and told the players that,” said Martin.

“It is the first time in some time I have done that. My throat was a little bit sore.

“The team is built on being really brave with the ball but really aggressive without and we lacked aggression.

“We were just a bit too nice, we’ve been horrible to play against for a while but we weren’t in the first half.

“At half-time it was about mentality and energy. Second half we were relentless and could have scored one or two more.”

Adams diverted a ball through to Mara and the Frenchman sent Daniel Bachmann the wrong way to finish at the near post and get Saints moving in the 52nd minute.

Six minutes later, Mara bagged his fifth goal of the season when he emphatically finished a counter-attack by thumping into the near post again, this time from outside the box.

Adams finally got the goal his persistence deserved when he calmly diverted Joe Rothwell’s sumptuous free-kick from the left flank past substitute Ben Hamer.

Saints could have made it a wider margin when Samuel Edozie and Sam Amo-Ameyaw struck the post.

The reward is a trip to Anfield, something to which Martin is looking forward.

“It will be exciting, it will be brilliant but we have five games before then,” he said.

“It is a great place to play football and to play against one of the best managers in the world in his last season there will be amazing.

“It holds a special place for me because I scored there on the day my son was born, probably the only point we ever took at Anfield in a fair few visits.”

Watford boss Valerien Ismael said: “It was disappointing, for sure.

“After the first half we were actually in the game. We knew coming here against a team with a lot of confidence and haven’t lost a game in a long time, we knew we had to be strong and solid.

“We grew up in the game and created some situations and told the guys we needed to step up and push for more.

“But in the second half after the first goal we mentally dropped quickly and had tiredness. We started to make mistakes and it became difficult for us to come back into the game.”