NORMAN, Okla. -- Oklahoma had developed a reputation for slow starts over the last few seasons.

After its slow start last season cost the Sooners a spot in the College Football Playoff, playing better early in the season became a point of emphasis.

At least Saturday, it looked like it paid off, as No. 7 Oklahoma blew out UTEP 56-7 at Oklahoma Memorial Stadium.

It was a successful start in Lincoln Riley's debut as the Sooners' coach as he took over in the offseason after 18 seasons of Bob Stoops being at the helm.

"It was fun," Riley said of celebrating the win. "Not because it was my debut, just because it was a great moment for our team. To finally just get out there and do what we love to do was fun.

"We enjoy winning here and don't take it for granted."

What made the Sooners go Saturday was not much different from what made them go the last two seasons.

Quarterback Baker Mayfield, who has finished in the top five in Heisman Trophy voting each of the last two years, was on from the beginning.

Mayfield completed 19 of his 20 passes for 329 yards and three touchdowns. That was especially encouraging for Oklahoma after it entered the game with little in the way of proven receivers.

"You can't get settled in with them (new receivers) if you don't trust them," Riley said. "You've got to give them chances. Baker did that today and gave those guys chances. He trusted them and those guys' confidence is gonna grow. Baker's confidence is gonna grow."

Mayfield didn't play after halftime.

Tight end Mark Andrews, about the only proven receiver for the Sooners, had a monster first half with seven catches for 134 yards and a touchdown.

Oklahoma jumped out to a 35-7 lead at halftime thanks to Mayfield's control, though he got some help from his receivers also.

The most notable assist came from Jeff Badet, who had to adjust after Mayfield underthrew him on a deep route. Badet was able to get a hand on the pass as he went up with UTEP's Kahani Smith, and tipped it into the air where he grabbed it for a 51-yard gain.

A play later, Mayfield hit Andrews for a 5-yard touchdown reception to put the Sooners up 28-7.

UTEP got off to a strong start offensively, methodically driving down the field for a touchdown on its opening drive.

The Miners slowed things down and mostly kept the ball on the ground as they tied the game with an eight-play drive that lasted 4:22.

"We were a little bit antsy, out of sorts," Oklahoma defensive coordinator Mike Stoops said. "Guys were trying to do too much. We were excited; we didn't play very fundamental football during that first drive, and that's what happens."

But Oklahoma scored touchdowns on four of its five remaining drives in the first half to take control.

"We weren't physically matching up with them and they wore us down, especially defensively," UTEP coach Sean Kugler said. "We had one nice drive offensively, and couldn't get it going after that."

Riley's predecessor, Bob Stoops, rarely pulled his starting quarterbacks before they had played at least most of the third quarter with games well in hand.

But Kyler Murray, who sat out last year after transferring from Texas A&M, played the entire second half at quarterback as Mayfield watched in a visor from the sidelines. Murray was 10 of 10 for 149 yards and a touchdown.

"I don't think the kids quit competing," Kugler said. "I think we were outmatched. Sometimes you've got to acknowledge that and move on."

NOTES: Oklahoma QB Baker Mayfield's 16 consecutive completions to begin the game was the most by a Sooners QB, breaking the record set by Jason White. ... UTEP LB Alvin Jones was ejected for targeting early in the second half for a hit on Oklahoma's Kyler Murray. ... Ten players caught passes in the first half for the Sooners. ... UTEP RB Walter Dawn Jr. ran for 49 yards and a touchdown on the opening drive, but had just 7 yards the rest of the way. ... The Sooners play at Ohio State next week while UTEP hosts Rice.