SAN DIEGO (AP) — Antonio Gates had three touchdown catches and the San Diego Chargers controlled the tempo to keep Seattle's offense off the field and upset the defending Super Bowl champion Seahawks 30-21 Sunday.

Gates' 21-yard catch late in the third quarter was epic, as the star tight end split two defenders and extended for Philip Rivers' pass, reaching out with his left hand to gather it in. Flat on his back, he held up the ball to show the ref he'd made the catch that gave San Diego a 27-14 lead.

Rivers was 28 of 37 for 284 yards.

San Diego (1-1) had blown an 11-point, fourth-quarter lead and lost its opener Monday night at Arizona. Seattle (1-1) had nine days to prepare after a 20-point opening victory against Green Bay.

Adding insult to injury, the NFL says league officials erred by not stopping play for a replay review after the Seattle's Percy Harvin scored on a 51-yard touchdown run.

The first-quarter play put Seattle ahead 7-3, its only lead of the day. Harvin took a pitch from Russell Wilson, got the edge and ran down the left sideline. But Harvin had stepped on the sideline during the run and the NFL said after the game the score was "incorrectly confirmed."

"Had the game been stopped for a replay review, the touchdown would have been reversed because Harvin stepped out of bounds at the San Diego 21-yard line," the league said.