SANTA CLARA—The Seahawks ran into a tough opponent on Sunday in the form of the 49ers, and facing a talented team, Seattle also got in its own way quite a bit, particularly in the first half. That combination proved to be too much to overcome for the Seahawks, who fell behind 20-0 in the first half on their way to a 27-7 loss at Levi's Stadium. 

Here are five rapid reactions to a loss that dropped Seattle's record to 1-1:

1. The Seahawks hurt themselves with some very costly first-half mistakes.

The combination of San Francisco's running game and its stout defense meant Sunday's game was going to be challenging for the Seahawks even if they had played a really clean game, which is not what Seattle did in this one.

The Seahawks fell behind 20-0 in the first half in no small part to hat the 49ers were doing to help themselves, but the Seahawks also got in their own way quite a bit, including two plays that, had they gone differently, could have drastically changed the way the game played out.

Late in the second quarter down 13-0, the Seahawks had their most promising drive of the game going, then tried a trick play in the red zone, one that backfield in a big way when running back DeeJay Dallas threw an interception to Charvarius Ward in the end zone. Seattle's defense came through with a stop right after that, setting up a chance for the Seahawks to get the ball back and try to cut into the lead, but on the punt that followed the defensive stop, Xavier Crawford was blocked into Tyler Lockett, leading to a muffed punt and a short field the 49ers would turn into a touchdown.

Add to that a lot of costly penalties that killed drives on offense and helped extend them for the 49ers—the Seahawks had 10 penalties enforced against them compared to one for San Francisco—and it was just a tough day for the Seahawks in a lot of regards.

2. The defense continued two trends from Week 1, one good and one bad.

While plenty of things went wrong for Seattle on Sunday, one positive on the defensive side of the ball was the way that unit once again held strong in the red zone. Yes, the 49ers were able to sustain some long drives, especially in the first half, but they were only able to score a touchdown on two of five trips in the red zone, with the other three drives ending in a pair of short field goals, as well as the field goal attempt that Tariq Woolen blocked and Michael Jackson returned for a touchdown.

That performance by Seattle's defense followed a Week 1 win in which the Broncos went 0 for 4 in the red zone, including two goal line stands by the Seahawks, and continues a trend going back to a 2021 season in which Seattle had one of the league's best red zone defenses.

Another trend from Week 1 that showed up on Sunday was not good for the Seahawks, however, and that was the way an opponent was able to move the ball on the ground. After Denver averaged 5.2 yards per carry in Week 1, Seahawks coach Pete Carroll pointed to the run defense as something he wanted to see his team clean up. Instead, the 49ers were able to move the ball well on the ground, particularly in the first half as they built a big lead. Seattle's defense held things down in the second half, which was particularly impressive given how long that group was on the field Sunday, but in the first half the 49ers were able to rush for 123 yards while averaging 6.5 yards per carry.

3. Cornerbacks Tariq Woolen and Michael Jackson teamed up for a big play.

With the Seahawks looking for a spark down 20-0 in the third quarter, Seattle's two starting cornerbacks made a big play, though on special teams rather than defense. With the 49ers lining up for a short field goal after another red-zone stop by the defense, Woolen used his combination of speed and length to get into the backfield coming off the edge, then Jackson, who had two fumble recoveries last week, scooped up the loose ball and took off for an 86-yard score.

It was the first time the Seahawks have scored off a blocked field goal since doing so in 2012, also against the 49ers, when Richard Sherman took a Red Bryant block back for a touchdown.

4. Tyler Lockett was a bright spot on a tough day for the offense.

The Seahawks offense struggled to get going against a really good 49ers defense—and when they did move the ball, they hurt themselves with penalties and turnovers—but on a day when not a lot went well for the offense, veteran receiver Tyler Lockett provided one of the bright spots.

Lockett, who is coming off of a career-best 1,175-yard season in 2021, was able to find open spots in San Francisco's defense, leading a nine-catch, 107-yard game. It was Lockett's 16th career 100-yard game in the regular season—he also has two in playoff games.

5. Uchenna Nwosu continues to be a very good addition to the defense, and Al Woods balled out.

Outside linebacker Uchenna Nwosu took home NFC Defensive Player of the Week honors for his play against Denver in Week 1, and while he didn't have quite as impressive of a stat line this time around, he was still a big factor in the game.

Nwosu wasn't able to add to his sack total, but he generated a lot of pressure, recording three quarterback hits, and he added to that four tackles and a pass defensed.

Al Woods, meanwhile, put up huge numbers for an interior lineman, recording seven tackles including three tackles for a loss, and he also had a pass defensed batting a ball down at the line of scrimmage.