Defending champion Mark Calcavecchia eagled the par-5 eighth hole and finished with a 7-under 65 on Friday to take the first-round lead in the Boeing Classic.
Steve Pate, Jeff Sluman, Joe Don Blake, Eduardo Romero and Kirk Triplett were tied for second at 68.
Calcavecchia, a playoff winner last year at TPC Snoqualmie Ridge for his first Champions Tour title, made a 20-foot putt on No. 8 after his 4-iron approach sailed over the flag.
''Had that not gone in, I still would have made birdie and been 4 under,'' he said. ''It went in, which is great. Then, like I always do, I tried to stay aggressive, keep making birdies and shoot low as I could.''
Calcavecchia birdied two of the first three holes on the back nine and got to 8 under. But on the par-5, 498-yard 18th, he found the sand twice and took a bogey 6.
''Taking a 6 on an easy 5 kind wrecked an otherwise great day,'' he said. ''I had a great score but you hate doing that. All in all, I played great, hit a lot of great shots.''
Calcavecchia won the Montreal Championship in June for his second victory on the 50-and-over tour.
Fred Couples withdrew because of back problems on the first hole. He won the Mississippi Gulf Resort Classic in March and Senior British Open last month.
''I didn't feel very good warming up,'' Couples said. ''I hit the tee shot at No. 1 and then my lower back really locked up when I walked down to my second shot.
''It was like a bomb went off in my lower back. It's time to rest. I'm sad I won't be able to play in this year's event. For this to happen in Seattle, this is a rough one.''
Calcavecchia's three-stroke lead is the biggest after the first round in the eight-year history of the event and the largest on the Champions Tour this year.
Also, the first-round leader in tournament history never won the title.
''My first rounds lately haven't been very good,'' Calcavecchia said. ''So I rectified that situation at least a little bit.''
Bernhard Langer shot an even-par 72. He won in 2010, shooting 66-63-69 to match the tournament record at 18 under.
PGA Tour winners Duffy Waldorf and Gene Sauers made their debuts on the Champions Tour. Sauers opened with a 71, and Waldorf shot 75.
