CLEMSON, S.C. (AP) — Boston College coach Steve Addazio thought his team had hung steady and headed into the second half toe-to-toe with the country's fifth-ranked team.

That's when things fell apart for the Eagles.

Addazio said the Eagles battled a pumped up Clemson and their own mistakes as a seven-point deficit grew to 24 in a 34-17 loss to the Tigers on Saturday night.

"We had some real tough stuff go against us on third down when we were off the field and penalties really got us," Addazio said.

Boston College (3-4, 0-4 Atlantic Coast Conference) trailed 17-10 at halftime and Addazio said he felt good at the break, thinking his team could continue handling the Tigers. That's when things did not break the Eagles' way.

An interception that at first appeared to hit off Hunter Renfrow's hands and into those of Boston College defender John Johnson with Clemson driving was overturned on review — the ball did touch the ground — and set up Greg Huegel's 39-yard field goal to extend the lead to 20-10.

On the Tigers' next series, quarterback Deshaun Watson overthrew receiver Ray-Ray McCloud on third down. But safety Gabriel McClary was called for pass interference to keep the drive going and Clemson cashed in on Watson's 51-yard TD pass to Artavis Scott.

The Tigers were again off the field when Watson threw wild on third-and-12. And again, a Boston College error kept Clemson going, this one a roughing the passer call on a high hit to Watson after he had released the ball.

Watson finished that drive with the last of his three TD passes, a 6-yard toss to tight end Jordan Leggett to go up 34-10.

Boston College didn't have nearly enough to fight back.

"Without those third-down penalties, I think we're right in this game," Addazio said. "I'm not trying to make lemonade here, I'm just telling you, that's how I felt."

Watson accounted for four touchdowns (three passing, one rushing) and a season-high 420 yards passing in Clemson's win. The Tigers put up 532 yards of offense against Boston College, which came in as the country's No. 1 defense — allowing 140 yards a game. The Eagles hadn't given up 500-plus yards since losing to Arizona State in the Independence Bowl after the 2013 season.

"Not every team can say they're playing the No. 1 (defense) in the country," Watson said. "We wanted to score points and show them what we had."

The Tigers improved to 6-0 (3-0 ACC) for the third time in five seasons. Watson finished 27-of-41 and Scott had 10 catches for 162 yards.

"Man, we came alive," Clemson coach Dabo Swinney said.

The Eagles opened 0-4 in league play for the first time since 2012, when they finished 1-7 in the ACC. Jeff Smith, Boston College's first true freshman to start since Chase Rettig in 2010, struggled throughout to move the offense against Clemson's defense.

Smith finished 7-of-22 for 87 yards and a 1-yard touchdown run in the game's final two minutes.

"I thought we came out hard, playing hard," Addazio said. "I thought we made some strides in certain areas. We thought we could move the ball against a great defense."

Instead, it was Clemson's defense, which ended last year No. 1 overall, that proved to be better.

"I definitely think we made that case," Clemson safety Jayron Kearse said.

Watson was far from perfect — he threw two interceptions that led to the Eagles' first 10 points — and was off target on his long throws early on. Still, the sophomore steadied himself and led the Tigers to their 34th straight win over an unranked opponent and a school-record 14th consecutive win at Death Valley.