Southampton’s manager, Claude Puel, joked it would take four defenders to stop Manolo Gabbiadini from scoring as the Italian continued his hot streak.

The Saints responded to their EFL Cup final loss to Manchester United with a win that featured Gabbiadini’s sixth goal in four games since his move from Napoli.

Gabbiadini scored twice at Wembley and had another ruled out, incorrectly in Puel’s opinion, for offside. The manager said: “It was difficult for him today. He played against three centre-backs. The next time it will be four centre-backs, but he continues to score. It’s important. He scored seven goals – three goals against Manchester.

“It’s fantastic work. All this gives good confidence for the team. It’s important to continue this way.”

Nathan Redmond scored twice – his first Premier League goals since October – and Dusan Tadic was also on target for Saints. Redmond could be called up for England’s matches with Germany and Lithuania this month.

“It was time. I’m happy for Nathan,” Puel said. “Nathan doesn’t score a lot of goals and he has all the qualities for this. I hope these two goals give him confidence for the future. He can become a strong striker for the national team. For the moment it’s important he continues his work and continues to make progress.”

Puel praised his players’ response to the Wembley disappointment, but lamented the lack of forthcoming action. Saints’ previous Premier League game was the 4-0 win at Sunderland on 11 February and their next is at Tottenham on 19 March.

Troy Deeney gives Watford an early lead at Vicarage Road. Photograph: Yui Mok/PA

Puel said: “I’m happy for my players. It was a difficult game to prepare for after the final and after the disappointment. It was very important to win, to keep a good level, a good position in the table for the future. We cannot play for two weeks. This is difficult to keep a good attitude and good intensity in training sessions.”

Gabbiadini’s goal came after Stefano Okaka had levelled the contest at 2-2 with 11 minutes to go. The Italian pounced on Heurelho Gomes’s error and Redmond struck for the second time to give Saints a two-goal lead.

There was a nervy conclusion as Abdoulaye Doucouré netted in stoppage time, but Saints held on.

The Watford manager, Walter Mazzarri, refused to blame Gomes for not holding Sofiane Boufal’s shot saying: “Mistakes can happen to all. We are a whole team and in these cases I don’t say anything.”

Troy Deeney had given Watford a fourth-minute lead with his 100th league goal for the club. Mazzarri said: “It’s a pleasure for Troy for sure and we’re happy for him. Even he would’ve liked that his goal would’ve brought one point or three points for the team.”

The Hornets also have two weeks until their next game against Crystal Palace.

The Italian warned his side could yet be dragged into the relegation battle. “I don’t want in the head of my players that they are already safe from relegation.”