The Eagles kept their perfect record intact on Thursday night in Texas, and their eighth straight victory to start the campaign set a new franchise record.
Offensive tackle Mailata, the 25-year-old former South Sydney Rabbitohs under-20s forward, provided plenty of protection for quarterback Jalen Hurts.
Siposs, the Eagles punter from Melbourne who played 28 AFL games for St Kilda between 2011-15, was called upon three times and kicked for a 50.3 yard average.
Philadelphia QB Hurts threw for 243 yards and two touchdowns in his first career game at NRG Stadium. Hurts, who was born in Houston and grew up about 40km from the stadium, continued his solid play in his homecoming to win his 11th straight regular-season game, which is the longest active streak in the NFL.
The Texans took an early lead when rookie Teagan Quitoriano, who was making his NFL debut, grabbed his first career reception for a two-yard touchdown on the first series.
Philadelphia tied it at seven on a two-yard run by Miles Sanders, who finished with 93 yards rushing, late in the first quarter.
The Eagles put together a 10-play, 79-yard drive capped by a four-yard TD run by Kenneth Gainwell to take a 14-7 lead before Houston tied it less than a minute before halftime when Davis Mills connected with Chris Moore on a 13-yard touchdown pass.
C.J. Gardner-Johnson grabbed his NFL-best and career-high fifth interception before Hurts threw a 17-yard touchdown pass to A.J. Brown to give the Eagles the lead in the third quarter.
Houston (1-6-1) added a field goal but another scoring toss by Hurts to Dallas Goedert and his two-point conversion run extended the lead to 29-17 early in the fourth.
Mills threw for 154 yards with two touchdowns and two interceptions while Houston rookie Dameon Pierce ran for a career-high 139 yards to bounce back from a tough game last week, when he gained just 35 yards on 15 carries.