The Texans last win over New England came in January 2010 as they maintained their one-game lead atop the AFC South Division.
"It is a big one," said Watson. "We can play with the top teams in the NFL."
Watson also welcomed the opportunity to go head to head with Patriots quarterback Tom Brady and come out on top.
"That's the (greatest of all time)," he said of Brady. "It is special for me. Before he hangs it up I had to at least get one (win) on him. I had to get this one."
Watson, who finished 18 of 25 for 234 yards, is just the third player since 1970 to have three touchdown passes and a touchdown catch in the same game.
Watson scored the first receiving touchdown of his career when he snared a flip pass from teammate DeAndre Hopkins as the Texans trick play worked in the fourth quarter.
"We been practicing that play for the last four weeks," he said. "It was the perfect time. I saw him look and I wanted to check out of it, but I thought, no we are going to make this work."
His 14-yard touchdown pass to Duke Johnson with 38 seconds left in the first quarter gave the Texans the lead for good.
Brady completed 42 of 47 passes for 326 yards.
In a clash of Super Bowl contenders, Ravens quarterback Lamar Jackson completed just 14 of 23 passes for 105 yards in rainy weather that he admitted "messed with me a lot."
But he ran for 101 yards and a touchdown to help the Ravens improve to 10-2 for the first time in franchise history.
Tucker's game-winner was his 38th straight fourth-quarter field goal, the longest active streak in the league.
"I was glad I made the kick man," said Tucker, who was promptly hoisted onto the shoulders of his celebrating teammates.
"These are as tough of conditions as we've had to make kicks in before ... being able to come through when it's really tough, it's extra satisfying."
The Ravens had taken over at their 35-yard line with 6:28 to play and advanced just nine yards on their first three plays.
Going for it on fourth down, Jackson got the first down on a quarterback sneak as the Ravens put Tucker in range.
"That golden leg. I got all the faith in him," Jackson said. "I'm on the sideline praying, but at the same time I know Tucker can do it."
Quarterback Andy Dalton, benched a month ago, returned to lead the Bengals, who snapped an 11-game losing streak.
Dalton completed 22 of 37 passes for 243 yards and a touchdown and the Bengals defense held the Jets -- who had scored 34 points in each of their last three games -- to two field goals.
The Jets became the first team in NFL history to lose twice in one season to teams with records of 0-7 or worse.
The Cleveland Browns' playoff hopes dwindled with a 20-13 loss to NFC North division rivals the Pittsburgh Steelers.
Their clash came 18 days after a brawl erupted in a Cleveland win over Pittsburgh -- a melee that saw Cleveland defensive end Myles Garrett suspended indefinitely for his helmet swinging attack on Steelers quarterback Mason Rudolph.
With Rudolph on the bench, rookie Devlin Hodges made his second regular-season NFL start and passed for 212 yards and a touchdown in the victory.
Also, quarterback Patrick Mahomes passed for 175 yards as the Kansas City Chiefs used a strong defense and a precision offense to dominate the Oakland Raiders 40-9 at Kansas City, Missouri.