Cincinnati, OH (Sports Network) - Adam Dunn homered for the fourth straight game and Edinson Volquez pitched six solid innings to win his third consecutive start, as the Cincinnati Reds handed Cleveland's Cliff Lee his first loss with a 6-4 triumph at Great American Ball Park.

Joey Votto also homered, Brandon Phillips drove in a pair of runs and Ryan Freel scored twice for the Reds, who extended their season-high winning streak to six and swept the Indians for the first time since interleague play began. Paul Janish stroked three hits and scored a run in the victory, while Ken Griffey Jr. also knocked in one.

"This is what we thought that we were capable of doing," Dunn said. "The only difference between what we're doing now and what we weren't doing early in the year is hitting. We're still getting the same great pitching."

Volquez (7-1), who had not yielded more than one earned run in any of his first eight starts, surrendered two runs -- both earned -- on four hits with four walks and five strikeouts. He had tied a big league record for most starts to begin a season without allowing more than one earned run, last accomplished by Mike Norris of Oakland in 1980.

Meanwhile, Lee (6-1) had won his first six starts before a no-decision six days ago against Toronto, in which he threw nine scoreless innings. He had not allowed an earned run over 30 2/3 innings of four road starts entering the contest, but on Sunday was charged with six runs -- five earned -- on 10 hits in just 5 2/3 innings.

"I don't feel like I was locating the ball as well as I have been the last few starts," Lee said. "I made a couple of bad pitches and we lost."

Lee, who fell to 10-2 lifetime in interleague play, saw his earned run average balloon from 0.67 to 1.37. Volquez, meanwhile, watched his ERA rise from 1.12 to 1.37.

According to Elias Sports Bureau, Sunday's pitching matchup was just the third in big league history between the ERA leaders in each league. The first came in 1998 when Al Leiter of the Mets faced Hideki Irabu of the Yankees and the second was four years later when Boston's Derek Lowe opposed Atlanta's Tom Glavine.

Michael Aubrey homered for Cleveland, while Jamey Carroll, Victor Martinez and Casey Blake each drove in a run in defeat.

The Indians put their first two batters on base to start the game, but Volquez struck out David Dellucci before Martinez lined into a double play.

Cincinnati then scored an unearned run against Lee in the bottom of the inning. Freel led off with a single and Janish walked before a passed ball advanced the runners. Griffey struck out, but Phillips grounded out to second to chase home Freel before Edwin Encarnacion popped out.

The Indians wasted a leadoff double by Ben Francisco in the second, walking Blake intentionally to get Lee as the third out. The same option came around in the fourth when Asdrubal Cabrera drew a two-out walk and stole second with Blake at the plate. Instead of again walking Blake to get to the pitcher, the Reds pitched to Blake, who lined a single to left field to score Cabrera with the tying run.

Dunn, though, clubbed a two-out homer in the bottom of the inning to put the Reds back in front. It was Dunn's 10th homer of the season and also the first earned run allowed by Lee on the road this year.

Cincinnati tacked on two more in the fifth with a two-out rally. Lee retired the first two batters, but Freel singled and raced to third on a base hit by Janish. Griffey and Phillips followed with consecutive run-scoring singles to make it a 4-1 game.

Aubrey's first career homer in sixth pulled the Tribe within two, but Javier Valentin doubled with two outs in the bottom half and Votto, batting for Volquez, connected for his ninth home run to increase Cincinnati's lead to 6-2 and chase Lee from the contest.

The Indians took advantage of the Cincinnati bullpen to score twice in the seventh. Jhonny Peralta led off with a single and Grady Sizemore doubled before Carroll singled off the pitcher to score a run. Martinez singled against new pitcher Jared Burton to knock in another run, but Francisco flied out and Aubrey grounded out to keep it a two-run game.

Ryan Garko had a chance to give Cleveland life leading off the eighth, drilling a ball off the base of the wall in left field. However, he didn't run hard out of the box and was thrown out at second base by Dunn.

Francisco Cordero walked Travis Hafner with two outs in the ninth, then completed an 11-pitch at-bat with a strikeout of Martinez to collect his ninth save.