Weaver (6-5) allowed three runs, seven hits and two walks through 7 1-3 and struck out five, including the side in the fifth. His streak of consecutive scoreless innings at home was snapped at 26 1-3 when Brett Lawrie led off the third with his ninth home run, but the right-hander still improved to 8-2 lifetime against the Blue Jays.
Weaver had an opportunity to become the first pitcher in the Angels' 53-year history to make four consecutive home starts without giving up a run, after blanking Boston through 5 2-3 innings, Oakland through eight and Minnesota through seven. But Lawrie drove a 1-0 pitch into the left field bullpen, only the second home run against Weaver in his last eight outings.
Esmil Rogers (3-6) gave up seven runs - five earned - and 10 hits over five innings. The right-hander is 0-4 with a 6.60 ERA in his last eight starts after back-to-back wins against Texas and Colorado.
The Blue Jays, trying to avoid finishing last in the AL East for the first time since 2004, are a season-worst 16 games behind first-place Boston and 7 1/2 behind the fourth-place Yankees. Manager John Gibbons, who has used his bullpen more than any other team, has gotten only 11 innings combined from his starters through the first three games of this series - including 2 1-3 by Josh Johnson and 3 2-3 by and Todd Redmond.
The Angels grabbed a 3-0 lead in the first. Mike Trout extended his consecutive on-base streak to 34 games with a single, and scored when Mark Trumbo barely beat the relay to first by shortstop Jose Reyes on a potential inning-ending double-play grounder to second with the bases loaded. Erick Aybar and Chris Nelson followed with RBI singles.
Los Angeles extended the margin to 7-1 with a four-run fifth that began with a leadoff homer by Calhoun, who drove in the tying and go-ahead runs in Friday night's 7-5 win with an eighth-inning homer off All-Star reliever Steve Delabar.
Rogers hit Trout on the left arm two pitches later before giving up a single by Josh Hamilton and a run-scoring single by Howie Kendrick. Center fielder Colby Rasmus made a wide throw to the plate trying to get Trout, and catcher J.P. Arencibia threw to second trying to nab Kendrick - but his throw sailed over shortstop Jose Reyes and skipped between Rasmus and right fielder Jose Bautista, allowing Hamilton to score and Kendrick to circle the bases.
NOTES: Weaver has not issued an intentional walk since Sept. 4, 2009, against Mark Teahen at Kansas City. Since then, he has faced 3,100 batters in 779 innings without giving up a free pass. ... Angels LHP Jason Vargas, who hasn't pitched since June 17 because of a blood clot under his armpit, threw 50 pitches in a three-inning simulated game and reported no discomfort. ... Weaver has 1,197 career strikeouts in 1,416 2-3 innings, and needs 18 punchouts to surpass the total his brother Jeff had in 1,838 innings in the big leagues. ... The Angels grounded into two double plays, increasing their total to a major league-worst 106.