HOUSTON (AP) — This is the Mario Williams the Houston Texans have been waiting for.

Last year’s top overall pick returned a fumble for a touchdown and had five tackles including two sacks to help the Texans to a 20-3 win over the Kansas City Chiefs on Sunday.

Matt Schaub had a successful, if a bit inconsistent debut in Houston, going 16-of-22 for 225 yards with a touchdown and an interception.

The Texans led 10-0 when Jamar Fletcher knocked the ball out of Kris Wilson's hands which Williams recovered. The 6-foot-7, 285-pound defensive end got up and rumbled 38 yards for the touchdown.

Linebacker DeMeco Ryans jumped on Williams to congratulate him, a far different celebration than last season when Williams endured endless criticism in part because the Texans passed on Reggie Bush and Vince Young to get him. Kansas City challenged the ruling of a fumble, but the call was upheld causing a roar from the sellout crowd.

Both of Williams’ sacks came after halftime, the second a 6-yard loss on second down inside the 20 that forced the Chiefs to settle for a field goal two plays later. Justin Medlock's 27-yarder made it 17-3 in the third.

Houston’s effort was helped by a slew of errors by the Chiefs offense. Kansas City fumbled three times, losing two of them, missed a short field goal and Damon Huard threw two interceptions. In addition, the Chiefs receivers dropped a number of passes.

Even with Larry Johnson back on the field, the offensive problems that dogged the team in a winless preseason where the Chiefs scored just two touchdowns continued. Johnson finished with 10 carries for 43 yards.

Huard’s first interception came just before halftime when Von Hutchins drilled Jeff Webb who tipped the ball which Dunta Robinson grabbed. First-round pick Dwayne Bowe dropped a couple of passes but had a nifty 25-yard catch that set up Kansas City’s only score. Huard was 22-of-33 for 168 yards.

The Texans offense wasn’t particularly impressive, considering the interception, a fumble by the normally steady Andre Johnson and a continuation of the protection problems which have plagued the team. Schaub was sacked two times and hurried plenty more.

He was impressive in flashes though.

Schaub found Andre Johnson up the middle for a career-long 77-yard touchdown reception that made it 10-0 midway through the second quarter. Johnson, who had seven receptions for 142 yards, tiptoed out of an arm tackle by a diving Bernard Pollard and jogged into the end zone.

The backup to Michael Vick for three years in Atlanta, Schaub also avoided the rush to find rookie Jacoby Jones for a 26 yard gain in the first quarter. He engineered a nice drive after Medlock missed a 30-yard field goal attempt in the first quarter, but the Texans came away empty-handed when Jarrad Page intercepted an ill-advised throw into the end zone.

Eddie Drummond fumbled a punt which Houston’s Charlie Anderson recovered in the second quarter and the Texans cashed in on the mistake with a 26-yard field goal by Kris Brown which made it 3-0.

Brown added a 28-yard field goal for Houston in the fourth quarter.