Education Commissioner Michael Williams announced Friday he was continuing the suspension of the rule at least until the 2013-2014 school year.
The move comes a day after Gov. Rick Perry, who appointed Williams in August, suggested ending the practice of including the test in final grades completely.
Lt. Gov. David Dewhurst and Sen. Dan Patrick, a tea party favorite who chairs the chamber's public education committee, also wrote Williams a letter backing a proposal to leave application of the so-called "15 percent rule" up to local school districts.
Williams' announcement at an Austin conference of experts on standardized testing caused the hundreds packed into a hotel ballroom to rise to their feet and applaud. The state's highest-ranking public-education official then held a copy of his order over his head and grinned while many in the room snapped pictures.
"Applause always makes you feel good," Williams joked to reporters moments later. "But we're not trying to pat ourselves on the back. We're trying to do what we think is the right thing for kids and moms and dads, and I think, in that regard, it is the right decision."
Federal data released this week showed that Texas tied with five other states for the third-highest on-time graduation rate in the nation for the Class of 2011 -- though the high rank was due in part to a change in the way states report their data.
The 15 percent rule has been backed by statewide business groups who say Texas is not producing students that are prepared for today's high-tech workforce and that cementing standardized test results in their grades is the only way to ensure kids will take the test seriously.
But lowering the stakes when it comes to how students fare on the exams -- known as the State of Texas Assessments of Academic Readiness, or STAAR -- has bipartisan support in the state Legislature. Parents have backed the idea, too, afraid that lower test scores could hurt their kids' grades enough that they won't be accepted by top colleges.
Created in 2009 and implemented last school year, STAAR replaced the much-maligned Texas Assessment of Knowledge and Skills exam.
Amid a firestorm of controversy last year, Williams' predecessor gave high school students a one-year break from the requirement this school year after more than 50 percent of freshman failed the STAAR writing exam.
Friday's deferral gets them off the hook this year, too. Students still must take the test and score well enough in order to graduate down the road.
Williams' decision -- backed by Perry, Dewhurst and Patrick -- only gives individual school districts the option of waving the 15 percent rule for their students, but more than 1,100 out of the roughly 1,200 statewide districts did so last year. Williams said he expects at least that many to do so again.
Some tea party lawmakers have called for a full moratorium on all standardized testing in Texas -- something that would be difficult given federal accountability requirements.
Williams insisted that Friday's move was not the first step down that path.
"I think there has been some call for that but I hope that we don't get to that point," he said. "Taxpayers want to know that they are getting bang for their buck ... kids want to know how they compare with the kids sitting next to them."
The State Board of Education has also recommended scrapping the 15 percent rule altogether, something the state Legislature could do when it reconvenes in January. Williams would not say if he will call for reducing the final grade requirement to perhaps 5 percent or suggest getting rid of it as Perry and others have suggested.
But, he added, support for the reprieve is "a recognition that a number of (state lawmakers) have been hearing from their constituents."
Though he has only been on the job three months, Williams has already made headlines by saying he plans to modify Texas' system for rating schools so that it places more weight on how well districts close achievement gaps between minority and white students, as well as those kids from low-income families.
He said Friday he'd like a new rating system that considers standardized test scores, student improvement on those tests and post-graduation preparedness, but he said minority- and low-income-student achievement "would be more important than the other three."
"This is not part of some affirmative-action program, it's who we are as a state," said Williams, noting that almost 65 percent of Texas students are now black or Hispanic.
"We had larger urban districts in this state that, as recently as the early 1990s, didn't even test its African-American students," Williams said. "We are in a new era."