BALTIMORE (AP) -- Brian Roberts apparently finds it easier to hit home runs than to determine why the ball is suddenly jumping off his bat at an astonishing pace.
Roberts connected in the second inning off Nate Robertson for a 4-0 lead. It was the sixth home run of the season for the 5-foot-9 second baseman, surpassing his previous career high of five in 2003. He hit only four in 159 games last season.
"Obviously at this point, I can't really come up with words to explain what's going on," he said. "I've said over and over, I have no idea why it's happening and what's going on."
Roberts, who has at least one hit in all 14 games this year, went 1-for-4 with a walk and is batting .421. He is on a pace to hit 69 homers.
"When it's going good," Roberts said, "you just try and relax and let it keep going."
Or, as Baltimore manager Lee Mazzilli put it, "The kid's hot. Ride the wave."
Javy Lopez had three hits for the Orioles, who have won seven of nine. Baltimore took over sole possession of first place in the AL East, staying a half-game ahead of Toronto and moving a game in front of the Boston Red Sox, who come to Camden Yards for a two-game series Wednesday.
Sidney Ponson (2-1) allowed four runs and nine hits in six innings. In his previous start, Ponson surrendered nine runs in three innings at Tampa Bay.
"I was a little better than last time, but I'm still not happy," he said.
Ponson was replaced by Todd Williams, who pitched two scoreless innings. The right-hander has not allowed a run in all six appearances this season.
Robertson (0-2) gave up six runs and seven hits in 3 1/3 innings. The left-hander led Detroit with 12 wins last year but is winless in nine starts since Aug. 30 and has yielded 12 runs in his last two outings.
He issued five walks in his last start but just one this time.
"I thought he threw a lot of strikes. In terms of the ball-strike ratio, that was something I liked better," Tigers manager Alan Trammell said. "He improved there; it's too early to come to any conclusions."
Rondell White had two hits and drove in a run for the Tigers, whose three-game winning streak ended.
Baltimore took control with a four-run second inning. Consecutive singles by Lopez, Jay Gibbons and Luis Matos produced a run before Roberts hit an 0-1 pitch into the left field seats, giving him an extra-base hit in nine of his last 12 games.
"Prior to the Roberts' three-run homer, they had three two-strike hits. So give them credit," Trammell said. "Roberts has been swinging a hot stick, and looking back, that was the key. Right now, Roberts is probably as hot as anyone in the league."
Tejada led off the third with his fourth home run, and Baltimore made it 6-0 in the fourth.
Omar Infante hit a two-out RBI single in the fifth, but the Orioles scored twice in the bottom half. Palmeiro led off with his 552nd homer, the first this season, and Larry Bigbie hit an RBI double for an 8-1 lead.
Detroit catcher Ivan Rodriguez (stiff back) did not play. ... The Orioles have scored at least seven runs in five of their last six games, the exception a 13-3 drubbing by the Tigers on Monday. ... It was the first time in eight games that Detroit did not score first. ... Detroit's Dmitri Young extended his hitting streak to 11 games.