Gonzalez set down the first 10 Blue Jays batters before Donaldson connected on a 3-2 pitch in the fourth, his 18th homer and first since June 10.
''It threw me off my game,'' Gonzalez said. ''It kind of made me more cautious. Instead of attacking hitters I started nitpicking and I started falling behind.''
Gonzalez pitched around two walks in the fourth without allowing another run but gave up two runs in the fifth.
''I got away from my game of staying down in the zone,'' Gonzalez said. ''I started elevating balls.''
Gonzalez, who allowed a season-high six runs in a loss to Oakland in his previous start, finished his outing with a perfect sixth.
''It felt good getting a quick inning, boom, boom just like the first three,'' he said. ''It ended well.''
Gonzalez's outing might have finished on a high, but the game didn't end well for the Rangers, who left the tying run at third base in each of the final four innings. Texas went 2 for 15 with runners in scoring position and lost for the eighth time in 10 games.
''We've got to be better with runners in scoring position,'' Rangers manager Jeff Banister said.
Gonzalez (2-3) lost his third straight decision. He gave up three runs and four hits in six innings.
''It was a battle,'' Blue Jays manager John Gibbons said. ''They threw some pretty good pitching at us.''
Hutchison (8-1) allowed one unearned run and four hits in 5 2-3 innings. He improved to 6-1 with a 2.12 ERA in eight home starts.
Hutchinson ended each of the first four innings with a strikeout, stranding four runners.
Roberto Osuna got four outs for his second save as the Blue Jays beat the Rangers for the 12th time in 16 meetings.
''Osuna continues to just be unbelievable,'' Hutchison said of his 20-year-old rookie teammate.
Texas cut it to 3-1 on an RBI single by Elvis Andrus in the sixth. Hutchison left one batter later after walking Gallo to load the bases.
Loup left after Texas loaded the bases with three straight singles in the seventh. Beltre drove in the second Texas run with a grounder off reliever Bo Schultz, but Moreland ended the inning by grounding out.
Fielder went 2 for 4, his fifth straight multihit game. Fielder leads the majors with 33 multihit games.
Canadian actor Stephen Amell, from the TV show ''Arrow,'' has been promoting Donaldson's All-Star candidacy on Twitter and Facebook. Amell, who took batting practice before the game and hit a home run, was chatting with Donaldson in the Blue Jays clubhouse following the game.
Rangers: RHP Matt Harrison (back surgery) threw his second bullpen session of the weekend before the game and is scheduled to start at Triple-A Round Rock on Wednesday. ''I'm confident that's all I'll need,'' Harrison said. ... OF Josh Hamilton (left hamstring) could be activated off the DL in time for Monday's game at Baltimore. Hamilton started in CF at Round Rock on Sunday and left the game after two at bats.
Rangers: LHP Wandy Rodriguez (4-3, 4.06) gets the start as Texas begins a four-game series at Baltimore. RHP Bud Norris (2-6, 6.70) starts for the Orioles. Rodriguez is 4-0 with a 2.28 ERA in seven road starts.
Blue Jays: RHP R.A. Dickey (3-7, 4.88) faces RHP Clay Buchholz (5-6, 3.68) as Toronto begins a four-game series against Boston. Dickey has won just once in his past six starts. He's 0-2 with a 6.16 ERA in three starts against the Red Sox this season.