Washington Nationals' Ryan Zimmerman crosses home plate as Colorado Rockies catcher Wilin Rosario stands nearby after pitcher Josh Roenicke's errant pick-off throw during the sixth inning of a baseball game Saturday, July 7, 2012 in Washington. The Nationals won 4-1. (AP Photo/Alex Brandon)

WASHINGTON | Gio Gonzalez knew he wasn’t going back to the mound after throwing 102 pitches in 101-degree heat.

Washington Nationals’ Ryan Zimmerman crosses home plate as Colorado Rockies catcher Wilin Rosario stands nearby after pitcher Josh Roenicke’s errant pick-off throw during the sixth inning of a baseball game Saturday, July 7, 2012 in Washington. The Nationals won 4-1. (AP Photo/Alex Brandon)
Washington Nationals’ Ryan Zimmerman crosses home plate as Colorado Rockies catcher Wilin Rosario stands nearby after pitcher Josh Roenicke’s errant pick-off throw during the sixth inning of a baseball game Saturday, July 7, 2012 in Washington. The Nationals won 4-1. (AP Photo/Alex Brandon)

The game was tied in the middle of the sixth inning, so if Gonzalez was to get his 12th win of the season, the Washington Nationals needed to score against the Colorado Rockies before making three outs.

And that’s precisely what happened.

Gonzalez pitched six innings of three-hit ball, and the Nationals used a three-run sixth to post a 4-1 victory Saturday.

Gonzalez (12-3) won his fourth straight start to move into a tie with R.A. Dickey of the New York Mets for the major league lead in wins. He allowed one run, walked three and struck out six.

Gonzalez matched Livan Hernandez for most wins by a Nationals pitcher before the All-Star break. Were it not for the productive sixth inning, it never would have happened for the hard-throwing lefty who’s headed to the All-Star game for a second time.

“He didn’t want to leave with the game tied,” Washington manager Davey Johnson said. “I said ‘You’re done. You’re not talking me out of nothing and we’ll get you a win right here.’ Thank goodness we got him the win. He pitched great.”

Gonzalez’s desire to stay in the game had nothing to do with personal goals. He simply wanted a win, and figured he was best equipped to pull it off.

“It’s an honor to know the team won today,” he said. “That’s all that matters to me. It was a team win.”

Obtained in an offseason trade with Oakland, Gonzalez has been everything the Nationals could have possibly wanted.

“I don’t know what kind of run support he got there in Oakland, but he’s certainly been stingy giving up runs and hits here,” Johnson said. “He’s been very consistent. He’s been fun to watch.”

It was the fifth victory in six games for the Nationals, who own the best record in the NL. The only loss in that span came Friday night against Colorado in a game started by Washington’s Stephen Strasburg.

Only once this season have the Nationals lost successive games started by Strasburg and Gonzalez, on April 28-29 against the Dodgers, but through five innings this was anyone’s game.

Danny Espinosa led off the sixth with a double off Jeff Francis (2-2). After a single by Bryce Harper put runners on the corners, Ryan Zimmerman hit an RBI single off Josh Roenicke.

On a wild pitch, Zimmerman took off for second. Rockies catcher Wilin Rosario’s throw was off target, and the error enabled Harper to score from third.

Later in the inning, Zimmerman came home on an errant pickoff throw by Roenicke.

After Gonzalez left, three Washington relievers allowed three hits over three innings. Tyler Clippard worked the ninth for his 14th save.

Colorado finished with four errors, tying a season high. Dexter Fowler had three hits for the Rockies, who have lost six of eight and totaled 14 runs in their last seven games.

“Today wasn’t so much about pitching as it was our lack of offense and the fact that we threw the ball around a little bit in the sixth inning,” Colorado manager Jim Tracy said. “When you get six hits in a game and one guy gets three of them, there’s not a tremendous amount of offensive opportunity.”

Ian Desmond made it 1-0 in the second inning with his 16th home run, a drive that barely cleared the right-field scoreboard. The shortstop has five homers and 13 RBIs over his last 12 games.

During the game, however, the team announced Desmond would miss Tuesday’s All-Star game with a left oblique strain. He has been dealing with the injury since mid-June and will use the break to rest.

“It’s definitely a tough decision, one that we spent quite a few days kind of mulling over,” Desmond said. “But in the end I think it’s best for the team and best for myself to take the rest. I would hate to be two, three weeks down the road and something happened and I didn’t take the four days to rest my body and put the team first.”

Colorado tied it in the fourth. Michael Cuddyer hit a leadoff double, moved to third on a groundout and scored with a headfirst slide on rookie Jordan Pacheco’s sacrifice fly to right.

Both teams got a runner into scoring position in the fifth. Colorado wasted a two-out double by Fowler, and the Nationals came up empty after opening the bottom half with successive singles by Desmond and Tyler Moore.

NOTES: Harper was named to the All-Star team as a replacement for Miami’s Giancarlo Stanton. … Zimmerman has 18 RBIs over his last 13 games. … Fowler is on a 7-for-12 run over his last three games. … Jordan Zimmermann (5-6) takes the mound for the Nationals in the series finale against the Rockies and right-hander Jeremy Guthrie, who’s 3-8 with a 6.28 ERA but 2-1 with a 2.34 ERA lifetime against Washington. … Colorado’s Carlos Gonzalez went 0 for 4 with three strikeouts.