WASHINGTON -- Clint Robinson didn't know what inning it was and Stephen Strasburg wouldn't comment about his future.
The first career walk-off homer in the majors for Robinson came one batter after Danny Espinosa struck out, which promoted home plate umpire Brian Knight to eject Bryce Harper. In the fourth inning Harper had struck out looking and voiced his displeasure with Knight.
Robinson, a longtime minor leaguer until last season, admitted he thought it was the eighth inning when he came to the plate.
"You lose track of the inning sometimes (in the tunnel when preparing to pinch-hit)," Robinson said. "I really wasn't worry about the inning. I am just looking for a fastball in the zone I can drive."
The homer came on a night when several media outlets reported that Washington's Stephen Strasburg, the starting pitcher Monday, had agreed to a seven-year contract extension for the Nationals. The San Diego native was set to become a free agent after this season.
"That would be great. That would be awesome," said Robinson, when told of the reports.
Strasburg would not comment about those reports but he did have nice things to say about the nation's capital.
"D.C. has been great. We are very comfortable here. It has grown on us," said Strasburg, who is married with a small child.
Washington manager Dusty Baker also wouldn't confirm the Strasburg deal as the Nationals (20-12) snapped a four-game losing streak.
"If that is the case I am very happy," said Baker, who added he looks forward to managing Strasburg in the future.
The immediate future is not so pleasant for the Tigers (14-17), who lost their seventh game in a row. For the first time during that losing skid Detroit did not lose by four runs or more.
Detroit had two homers, by Nick Castellanos and J.D. Martinez, against Strasburg, who fanned 11 batters and did not figure in the decision as he gave up six hits in seven innings. He has struck out at least 10 batters in a game 24 times in his career.
"He is a good pitcher. I don't know if he did anything differently" after the homers, Ausmus said. "He pitched well. Nick and J.D. just happened to get a hold of a couple."
Strasburg, 27, did fan the side in the seventh as he retired nine batters in a row, six of them by strikeout. Strasburg walked Miguel Cabrera to lead off the eighth and was replaced by Blake Treinen.
The winning pitcher was Shawn Kelley (1-0), who got the last out in top of the ninth, while Lowe (1-2) suffered the loss.
Ben Revere of the Nationals had a sacrifice fly off reliever Kyle Ryan to tie the game at 4-4 in the seventh.
The Nationals had trimmed the margin to 4-3 with a two-run homer in the sixth by Daniel Murphy (two hits), who entered the game hitting .395 with 18 extra-base hits.
Detroit starter Anibal Sanchez entered the game with a lifetime mark of 9-1 and an ERA of 1.98 in 21 starts against Washington. He gave up four earned runs on six hits in six innings plus three batters Monday and also did not figure in the decision.
"I thought he ran out of gas," Ausmus said.
Martinez and Castellanos had two hits apiece for the Tigers.
Strasburg, the No. 1 overall draft pick of 2009, was set to become a free agent after this year and was pitching two days before former Washington right-hander Jordan Zimmermann, who left via free agency after 2015, is set to pitch for Detroit against the Nationals.
Castellanos cranked a 96 mph fastball from Strasburg just over the fence in left for a two-run homer in the first.
Murphy had an RBI single in the fourth to cut the margin to 2-1.
The Tigers took a 4-1 lead when Martinez lined a two-run homer to left in the fifth off Strasburg.
Harper began Monday with 12 plate appearances in a row without an official at-bat, with 10 walks, one hit by pitch and one sacrifice fly to set a major-league record. The streak came to an end when he grounded out to the pitcher for the last out of the first.
Harper was called out looking on strikes in the fourth and voiced his displeasure with home plate umpire Knight, who tossed him before Robinson ended the game.
NOTES: The Tigers called up OF Tyler Collins from Triple-A Toledo for his second stint with the team this year. Detroit sent RHP Buck Farmer to Triple-A after Sunday's game ... Detroit entered Monday with six losses in a row, having been outscored 43-16 ... The Nationals were coming off a three-city, 10-game road trip to St. Louis, Kansas City and Chicago in which they were 5-5 after losing the fourth of four games Sunday 4-3 to the Cubs in 13 innings ... Washington OF Bryce Harper, who tied a major-league record with six walks Sunday, entered Monday with an on-base average of .432 with 30 walks. Harper began Monday with 12 plate appearances in a row without an official at-bat, with 10 walks, one hit by pitch and one sacrifice fly to set a major-league record ... Washington RHP Stephen Strasburg entered the game with a record of 5-0 and an ERA of 2.36, while Tigers RHP Anibal Sanchez was 3-3, 5.87 ... Tigers RHP Michael Fulmer (1-1, 6.30) will face Washington RHP Joe Ross (3-1, 1.23) on Tuesday.