Five things we learned about the Lions in the 27-20 win at Washington on Sunday:

1. Rashean Mathis should be the starting cornerback not the reliever. He started instead of coming in from the bullpen for rookie Darius Slay like he did the first two games. Mathis, a veteran, was a big improvement. It’s tough to be a rookie cornerback in the NFL. This doesn’t mean the Lions have given up on Slay, but he’s not quite ready yet. On Sunday he didn’t play one snap at corner, he did see action (17 plays) on special teams.

2. We’ve known all along that Matthew Stafford is tough and he proved it again with a quarterback sneak on a fourth-and-1 at Washington’s 12-yard line in the fourth quarter. Two plays later Stafford connected with Calvin Johnson for a touchdown that gave the Lions a 10-point lead with 3:56 left in the game.

3. Matthew Stafford’s 385 passing yards gave him a total in three games of 1,040 which puts him on pace for 5,536 yards in 16 games. That would break the record currently held by Drew Brees who had 5,476 passing yards in  2011. Stafford is sixth and seventh with all time passing yards in a season — 5,038 in 2011 and 4,967 in 2012.

4. The Lions are just fine at wide receiver. So many fans were panicked in the offseason. Nate Burleson looks better than ever.  He had six catches for 116 yards Sunday. That gives him 19 receptions in the first three games which is tops on the team. Ryan Broyles made his season debut with three catches (on three targets) for 34 yards. Kris Durham only had one catch but it was for 33 yards. Oh, and Calvin Johnson who had seven catches for 115 yards and a touchdown.

5. Louis Delmas’ left knee does not appear to be slowing him down. He was on the field for every defensive play and finished second on the team with eight tackles — he had a combination of six in the first two games. Delmas only practiced one day last week but that’s enough for the safety. He just needs to be ready to go on Sundays.

(Follow @PaulaPasche on Twitter. Order her book,  “100 Things Lions Fans Should Know & Do Before They Die’’ here. It’s also available at bookstores.)