While Arsenal slipped up at West Brom and Manchester City were thrashed by Liverpool, United dug out a 2-1 victory at Vicarage Road thanks to an injury-time own goal from Troy Deeney.
Deeney thought he had snatched a draw when he cancelled out Memphis Depay's opener with an 87th-minute penalty, but the Hornets captain undid his good work by bundling in Bastian Schweinsteiger's shot-cum-cross minutes later.
Arsenal and City's defeats mean Louis van Gaal's side move second in the table, one point behind Leicester, and Lingard believes the gutsy win delivered a psychological blow in the race at the top.
"It's massive," Lingard told ManUtd.com
"It's a bit of a statement to the other teams, who will look at this and see we've won
It puts a bit more pressure on them, but it's a good feeling to be back up there.
"It was a great way to end the game
I thought it was a scrappy match overall, the conditions didn't help, but we had to keep our concentration throughout and it's great to get the win.
"There are a lot of games coming up, we've got a lot of injuries at the moment and have to adapt to that, I thought we did that well today
As long as we win as many games as we can over Christmas, I think we'll be fine."
It has been an encouraging fortnight for Lingard, who has now started all of United's last three matches as well as earning a late call-up to Roy Hodgson's England squad for the game against France.
The 22-year-old was lively on Saturday too, occupying Watford's defence with a number of dangerous runs in behind while combining well with fill-in forward Depay.
Van Gaal praised both players after the match but Lingard thought he should have put the game to bed before Schweinsteiger forced Deeney's error.
"We created a lot of chances, and personally I should have scored a couple of clear-cut chances," Lingard said.
"I've obviously got to work on that but it's great to see Basti at the back post to stick one in at the end
It's been a long time coming for him, and he's deserved it."
Source : PA
Source: PA