When Jon Lester took the mound last night, he was trying to become the first Red Sox lefty starter since 1973 to go at least 7-0 to begin a season.

But he also was facing his personal kryptonite.

In his best and worst seasons, Lester struggles against the White Sox. He can’t explain it, but it has become as predictable as winter blizzards in Chicago. In nine previous starts against the White Sox entering the series opener here, the Red Sox ace lefty had a 5.20 ERA, by far his highest against any AL team.

And, true to form, Lester got roughed up again in a 6-4 loss that snapped the Red Sox’ five-game winning streak.

“For whatever reason, I’ve never pitched well here,” Lester said after allowing five runs, all with two outs, over the first two innings. “Talk to them. See what they’ve got on me. Maybe you can get some info for me. It’s just one of those gigs. If I knew (why), I’d stop giving up a bunch of runs to these guys.”

One particular nemesis reared his head again in the White Sox’ three-run first inning.

Paul Konerko, 10-for-25 lifetime against Lester, worked a two-out walk to extend the rally for all-or-nothing slugger Adam Dunn, described by Lester as having “stupid pop.” And that power was on full display when Dunn blasted a hanging cutter over the right field fence for a 3-0 White Sox lead.

Lester lamented both the walk and the homer, although when it was suggested that walking Konerko may have been the best possible outcome given their history, he insisted he wasn’t going to give in or change his approach just because the White Sox have owned him.