Calen Carr and Brian Ching each scored as the Dynamo won their fourth straight with a 2-0 victory over Toronto at BMO Field.
Both goals came on defensive gaffes as Toronto played sluggishly after more than a week off since its last MLS game.
"The fight wasn't there, we made it too easy for Houston," said TFC forward Ryan Johnson. "They were beating us on second balls and there wasn't enough effort on our end. If we don't bring it against Houston, you're not going to beat them."
It snapped Toronto's season-high three-game surge and denied them a club-record fourth in a row. With the loss Toronto remains last in the MLS standings at 5-12-4.
The Dynamo moved up to second in the Eastern Conference at 10-5-7 and are now undefeated in seven games. Houston has conceded just one goal — a penalty — in its past six contests.
Toronto head coach Paul Mariner said before the game that Dynamo midfielder Brad Davis was the player he feared most going into the match. Davis proved those fears well-founded as he looked dangerous on set pieces and finished with assists on both goals.
"We really took advantage of our chances," said Davis. "Guys were willing to get behind the ball and get on the attack today and it worked out for us."
Toronto came out sluggish in the second half and never seemed to recover from conceding a late goal in the first. Davis sent in a corner kick in the 45th minute that Houston defender Bobby Boswell deflected to a wide open Carr. The Dynamo forward made no mistake and headed it in from the right side of the six-yard box to the bottom corner of the net, deflating the crowd of 19,652 fans.
"A terrible goal to concede, especially at that time," said Mariner. "That's when you should be on your mettle. The last kick of the half, you have to be resolute. Takes the wind out of us a little bit."
Recently-acquired forward Quincy Amarikwa made his BMO Field debut with the start at forward. He looked feisty in the 54th minute when he battled for position with the ball in the six-yard box, only to be taken down hard by two defenders. He looked to the refs but to no avail.
Houston continued to maintain possession in the second as midfielder Boniek Garcia fired in a left-footed shot in the 57th that went just wide to the left.
The Dynamo slowed down the pace to protect their lead, though TFC had a chance to level in the 73rd when midfielder Luis Silva put a deflected header just over the crossbar.
Houston widened its advantage in the 86th when Davis set up Ching with a beautiful touch pass and the Dynamo captain put it past TFC 'keeper Milos Kocic with ease to make it 2-0.
"Brian came on today and battled unbelievably hard, did a great job and got himself a goal," said Davis. "We've been a tough team to break down lately."
The defensive breakdowns on the backline put more pressure on TFC to bring in a centre back that Mariner insists the team desperately needs.
"We need it. I've been saying it for weeks," said Mariner. "But what is the point in having a 'panic buy'? We're here for the long haul, we're not her for 10 minutes. I'm hoping we get something done over the weekend."
Prior to the game, Toronto introduced newly-acquired striker Eric Hassli who came to the Reds via a trade last week with Vancouver. The 31-year-old Frenchman, however, was held out of the lineup to rest an ankle injury suffered while still playing for the Whitecaps.
He'll likely make his debut when Toronto opens its CONCACAF Champions League campaign on Aug. 1 at home against CD Aguila of El Salvador. TFC's next CONCACAF game will be Aug. 28 against Mexico's Santos Laguna, also at BMO Field.
"(Champions League) is a competition that's been good to us over the last couple years," said Reds midfielder Terry Dunfield. "It's great when you have a mid-week game after a poor performance. Hopefully we can put it right on Wednesday."
Notes: The Dynamo were missing top goalscorer Will Bruin who didn't play because of an injury. He leads Houston with 10 goals. ... Toronto already has more MLS wins since July 11 than in their opening four months of the season. ... Toronto parted ways with defender Miguel Aceval on Thursday and his contract was terminated by mutual consent. The Chilean made five league appearances this year and had two assists. ... Saturday was the second of three games between TFC and the Dynamo this season. The last game ended in a 3-3 draw on June 20 in Houston. They next meet Aug. 25 at BMO Field.