While Jeremy Guthrie may not completely fit that description, there's no denying he has pitched like an ace of late.Guthrie looks to match a career high by winning his fourth straight start as the Orioles conclude a three-game series against the Seattle Mariners on Wednesday night.Last-place Baltimore (42-78) has experienced a resurgence since Buck Showalter took over as manager Aug. 3, winning 10 of 15. The rotation has posted 12 quality starts and a 2.82 ERA during that stretch.No Orioles starter has been better lately than Guthrie (7-11, 3.88 ERA). The right-hander is 4-1 with a 1.51 ERA in six starts since the All-Star break, walking seven and striking out 24.Guthrie allowed two hits over six innings in a 5-0 road win over Tampa Bay on Friday."I had to battle. I didn't have a great feel for any of my pitches, " he said. "For the most part I made some important pitches at important places in the game."He last won four consecutive starts July 28-Aug. 13, 2008.Guthrie is 0-2 with a 5.29 ERA in three home starts against the Mariners despite posting quality starts in two of them.Kevin Millwood provided the Orioles with their latest strong outing Tuesday night. He worked eight solid innings but was outpitched by Luke French, who combined with Brandon League on a three-hitter in the Mariners' 4-0 victory.Substitute left fielder Matt Tuiasosopo hit a three-run homer and drove in all four runs for Seattle (47-73), which improved to 5-3 under interim manager Daren Brown.Tuiasosopo learned 20 minutes before the game that he would start in place of Ryan Langerhans, who was a late scratch with a severe headache."I just wanted to go out there, and ... find a way offensively or defensively to help this team win a game. Just be loose and have fun," Tuiasosopo said. "Gosh, it feels really good."Tuiasosopo came in with a .155 average, one homer and two RBIs in 71 at-bats."It's good to see him when he gets an opportunity like he did tonight," Brown said. "He's got a chance to be a good offensive player."Seattle will try to win its fourth straight series by sending David Pauley (1-4, 3.31) to the mound.Pauley earned his first major league victory Friday, 3-2 at Cleveland after allowing two runs over six innings. It was his 11th start and 19th career appearance.The right-hander appeared in nine games for Boston in 2008 and entered his sixth start of the season for Seattle with a career record of 0-7 and 6.40 ERA."I'm just grateful to get this opportunity," said Pauley, who signed as a minor league free agent in December and had a 1-6 record at Triple-A Tacoma before being called up June 27.The Orioles acquired Pauley from Boston on Jan. 19, 2009, but he didn't make an appearance for them. His only game against Baltimore came in relief with Boston on Sept. 2, 2008.