SEATTLE -- While recent conversations have surrounded Seattle's disappointing defense and quarterback Russell Wilson struggling to stay on two feet, it was a free-agent signing and a waiver claim that propelled the Seahawks to victory on Sunday night.

J.D. McKissic, inactive for the first three games this season, took his first carry of the year 30 yards to put Seattle ahead 25-18 in the third quarter.

"It's a tremendous thing (to contribute to the team), it's a huge thing for me," McKissic said, "but even if I didn't score tonight, I would still give it my all on special teams."

On the next play from scrimmage, defensive lineman Marcus Smith batted the ball out of Indianapolis Colts quarterback Jacoby Brissett's hand. Linebacker Bobby Wagner scooped the ball up and rumbled into the end zone for Seattle's second touchdown in 13 seconds, helping the Seahawks roll to a 46-18 victory over the Colts.

"The whole game I had been bull rushing (the tackle), we came to (the) sideline and Michael (Bennett) was like 'take him high and around' so the next time I took him high and around and got the sack fumble," Smith said.

"It felt great to get into the end zone," Wagner said. "Picked up the ball, made a few guys miss and got into the end zone."

Tight end Luke Willson scored on a 6-yard touchdown from Wilson early in the fourth quarter and McKissic added a receiving touchdown late to cap off the best performance of his career and the most points scored in a quarter in Seahawks history (36).

McKissic was signed off waivers late last year and came into the game with two carries for 5 yards in a Seahawks uniform. After no action in the first half, he finished the game with 38 yards on the ground, 27 through the air and two touchdowns.

"I wanted to take advantage of the opportunity and contribute to the team and help get this beautiful W," McKissic said. "I had the linebacker on me and I wanted to beat him. I knew Russell would go to me with a single-high (safety). I beat the linebacker outside and found the ball."

Wilson connected on 21 of 26 passes for 295 yards and two touchdowns with two interceptions while the Colts' Brissett threw for 157 yards with one touchdown and one interception.

Wilson also added a rushing score of his own, the first touchdown of the day for the Seattle offense. He ran straight down the middle of the field after dropping back for a pass and dived into the end zone, reaching the ball out for a score as he got hit hard on his left thigh.

Wilson's reaction was even better than the score itself, as he jumped up with a furious fist pump toward the home crowd in the north end and headbutts all around for his teammates.

"I think that as a competitor there's moments that get you going and get the team going as well," Wilson said. "I knew I was in, I felt I kept my legs up above the ground. That energy is what we need and it's not just for me."

Seahawks wide receiver Doug Baldwin was all too excited to see his quarterback get fired up after he sold out for that touchdown.

"That's the Russell we like, don't get me wrong he's always cool calm and collected, but, guys want to see that passion from him," Baldwin said. "If you ask me what was the spark, him getting up and celebrating the way he did, that gave a lot of juice to the rest of the team."

Seattle's defense, meanwhile, after giving up 205 yards of offense in the first half, limited the Colts to just 31 yards in the second half.

Seattle's Justin Coleman, playing nickel back after Jeremy Lane left in the first quarter due to a hip injury, took his first career interception to the end zone on the Colts' first drive of the second quarter to put the Seahawks up 10-2.

"I just played my responsibility," Coleman said. "When the play came my way, I felt like I had to take the opportunity and take advantage of it."

Two second-quarter scores put the Colts ahead 15-10 just before halftime. Brissett directed his team down the field on 80- and 55-yard drives. The first drive was capped off by Colts running back and former Seahawk Robert Turbin, when he punched in a 1-yard run in his return to CenturyLink Field. The two-point try failed.

The second touchdown came on an 18-yard fade route by wide receiver Donte Moncrief. It came after Wilson threw his first interception of the season to safety Matthias Farley, giving the Colts strong field position at their own 43.

Despite allowing a defensive score, the Colts dominated the game in the first half, nearly doubling Seattle's time of possession. Indianapolis had 205 yards of offense and two badly timed defensive holding penalties by the Seahawks kept the 80-yard drive alive.

A missed field goal by Seattle's Blair Walsh at the end of the half capped off a disappointing performance from the home team, which got booed off the field.

"We still knew there were 30 minutes left to go," Brissett said. "We know they're a good team. Obviously, they're one of the best teams in the league every year, so we've definitely got to come out there and play with the same type of fire we played with in the first half. One play here, one play there kind of slowed us down a little bit."

NOTES: Seahawks DE Cliff Avril (neck injury) and CB Jeremy Lane (hip) left the game during Seattle's second defensive series and did not return. ... Seahawks CB Justin Coleman got his first interception of his career in the first quarter and returned it for a touchdown. ... Colts RB Robert Turbin scored a touchdown in his return to CenturyLink Field. Turbin played for the Seahawks from 2012-14.