The Arizona Diamondbacks looked ready to add to their 17 comeback wins.

This time, they couldn't pull it off.

Left-hander Joe Paterson walked Rick Ankiel with two out and the bases loaded in the 11th inning, then yielded a grand slam to Mike Morse in a 9-4 loss to the Washington Nationals on Sunday. Paterson had scoreless outings in 23 of his 24 previous appearances.

"There were a lot of opportunities that were missed," Arizona manager Kirk Gibson said. "Guys played hard, they didn't give in. It was a great ballgame, we just didn't come out on top."

Gibson and Nationals manager Jim Riggleman were among four ejections, and Washington was hit by a pitch four times, including second baseman Danny Espinosa twice. The Nationals also blew a 4-0 lead.

"You've got to overcome difficult situations," Riggleman said. "Great at-bat by Ankiel, that was the key. That Paterson is tough on left-handers."

The Diamondbacks scored three times in the ninth inning to tie it at 4, but the Nationals bounced back in the 11th to earn a split in the four-game series.

Pinch-hitter Jerry Hairston Jr. led off with a single to center against Paterson (0-1). Pitcher Jordan Zimmermann then hit for reliever Sean Burnett (1-2) and moved Hairston to second with a sacrifice. Roger Bernadina reached on a high chopper and Jayson Werth walked with two out to get to Ankiel, who walked on five pitches.

"I just had to throw strikes to Ankiel and didn't do that," Paterson said.

Morse added his second career grand slam, a drive to center for his eighth homer of the season.

Burnett pitched 1 2-3 innings to get the win and Henry Rodriguez retired the Diamondbacks in order in the bottom half of the 11th.

Arizona had won 18 of 22 to surge into contention in the NL West and looked primed for another dramatic victory before the disastrous final inning.

The Diamondbacks got to Nationals closer Drew Storen for three runs in the ninth inning. They put their first three batters on before Juan Miranda walked to force in a run. Melvin Mora hit a sacrifice fly off Todd Coffey and pinch-hitter Xavier Nady tied it with a run-scoring fielder's choice.

Wilson Ramos hit a three-run homer in the eighth for the Nationals, who finished with 11 hits. Werth also had a sacrifice fly in the third.

Arizona's Kelly Johnson hit a solo shot off the foul pole in left in the bottom of the eighth.

The ejections became a footnote after the late-inning drama.

Werth, hit twice previously in the four-game series, was drilled in the arm in the fifth inning, above the same elbow that was struck Thursday night and caused him to miss Friday's game. Home plate umpire Rob Drake issued a warning to Diamondbacks starter Ian Kennedy.

"If you look at the whole game, we are not throwing at him," Gibson said. "We are trying to throw him tight. We don't want him to get his arms out. Espinosa the same way. I will show you the scouting report if you don't believe me."

When Kennedy threw too far inside and hit Morse two batters later, Drake allowed the pitcher to remain in the game. That brought Riggleman out of the dugout to have a word with Drake, but he said he was only lauding the umpire for his judgment.

"Once we give warnings, if we deem it's intentional then there are ejections. The rest of it will be in our report to the league," crew chief Gary Darling said, making clear Drake didn't feel Morse was hit intentionally.

Nationals starter Jason Marquis was working on a shutout in the sixth when he hit Justin Upton in the lower back with a pitch. Drake tossed Marquis and Riggleman.

Upton was hit with pitches four times in the series.

"I don't necessarily think there was intent, everybody is trying to win the ballgame but at some point the pitcher has to hit his spot," Upton said. "Getting hit three times in three days is pretty ridiculous. I am not mad about it, it's a part of the game."

Said Riggleman: "I can promise you we did not one time have any intent to hit Upton. I feel terrible he got hit four times. Clearly we feel that when there was an open base, they took some shots at Werth. ... We're not throwing at anybody. We're trying to win the game."

Drake ejected Diamondbacks reliever Esmerling Vasquez after he plunked Espinosa with one out and a runner on in the eighth. Gibson also was tossed.

"None of it was offensive to me. It was a very intense baseball game today," Gibson said. "It was entertaining, it was well-played and unfortunately someone had to lose, and unfortunately it was us."

Ramos greeted Aaron Heilman with a home run to left field, and the catcher took his time circling the bases amid boos from the crowd at Chase Field. Riggleman said Ramos was slowed by a leg injury.

"He gutted it out to stay in the game," Riggleman said.

NOTES: Nationals 3B Ryan Zimmerman was scheduled to make a rehabilitation appearance with Class-A Hagerstown. Zimmerman has missed 52 games since being placed on the 15-day disabled list April 12 with a left abdominal injury ... Werth made a leaping catch against the fence in right-field foul territory in the bottom of the fifth to retire Miranda.