Ryan Fitzpatrick threw for a franchise-record six touchdowns, and Hopkins had a career-best 238 yards receiving and two scores as the Texans set a team-record for points, rolling to a 45-21 win over the Tennessee Titans on Sunday.
Hopkins, a first-round pick in 2013, leads the team with 1,041 yards receiving and six touchdowns.
''I'm just happy to see the kid grow as a player,'' Johnson said. ''Comparing this year to last year, it's amazing. It's fun to watch.''
Fitzpatrick started after being benched for two games for Ryan Mallett, who sustained a season-ending chest injury last week.
Hopkins caught a 58-yard touchdown pass to extend Houston's lead to 24-0 just before halftime. The second score by Hopkins made it 31-14 later in the third quarter.
He said learning from Johnson, a seven-time Pro Bowler, has helped his improvement this year.
''I develop from sitting there talking to him every day,'' Hopkins said.
Fitzpatrick passed for 358 yards and came up one short of tying the NFL record by throwing touchdown passes of 8, 7, 58, 34, 4 yards to his receivers before ending his day with a 1-yard TD toss to J.J. Watt.
The quarterback raved about Hopkins.
''He makes plays,'' Fitzpatrick said. ''He is a pretty special player. We've got two great ones on the outside, so they've got to figure out (Sunday) what the matchup was.''
Watt had his third touchdown reception, two sacks, forced and recovered a fumble for Houston (6-6).
Tennessee's Zach Mettenberger injured his right shoulder playing behind a makeshift offensive line missing three starters. Jake Locker took over in the third quarter and threw for 91 yards with a touchdown and two interceptions for the Titans (2-10), who have lost six straight.
Here are five things to know about Houston's big win over its AFC South foe.
METTENBERGER SHOULD BE OK: Mettenberger said he has a sprain and thinks he will be able to play next week, but that he'll have an MRI on Monday.
''As minor as it seems right now we'll get it straightened out (Monday),'' he said. ''Hopefully I can put myself in a situation to play next week.''
The rookie finished with 184 yards passing with a touchdown and an interception to remain winless in five career starts.
WATT FOR MVP?: After another big game from Watt, almost everyone from his teammates to the owner of the franchise was campaigning for the defensive end to be the first defensive MVP since Lawrence Taylor in 1986. Watt has 11 1/2 sacks and five touchdowns to make him the first player to have at least 10 sacks and three or more touchdowns in a season since 1982, when sacks became an official statistic.
''He's just unbelievable and he continues to amaze all of us,'' Texans owner Bob McNair said. ''I think he's deserving of that kind of consideration, and I think that would be wonderful.''
THE WRIGHT STUFF: Tennessee receiver Kendall Wright was a bright spot in a dismal day for the Titans. He finished with seven catches for 132 yards and a touchdown. It was his third career 100-yard game and he has 51 receptions this season to make him just the second player in team history with at least 50 receptions in each of his first three NFL seasons.
FOSTER'S RETURN: Houston running back Arian Foster returned after missing the last two games with a groin injury and finished with 79 yards rushing and 26 yards receiving with a touchdown.
''He does a lot of things,'' coach Bill O'Brien said. ''Obviously running the ball, but (also) blitz pickup, third down, catching the ball in the backfield. He's done a lot for our football team this year, so it's good to have him in there.''
LINE WOES: The Titans were missing rookie left tackle Taylor Lewan (ankle), center Brian Schwenke (knee), who was placed on injured reserve on Tuesday, and right tackle Michael Oher (toe), who was active but didn't play on Sunday. Coach Ken Whisenhunt didn't provide an update on any of the injured linemen after the game and right guard Chance Warmack's status is unclear after he injured his ankle late in Sunday's game.
''With new guys stepping in, we've got to pick it up on the line,'' left guard Andy Levitre said. ''We've got to have more attention to detail, more focus. We've got guys who have been here a long time and are fairly new to this offense so our attention to detail has to be that much greater.''
AP NFL website: www.pro32.ap.org and www.twitter.com/AP-NFL