TORONTO — R.A. Dickey couldn't explain why he struggled so much through one of the shortest outings of his career on Saturday.

He said his knuckleball, an unpredictable pitch on its best days, felt good at the beginning of the game. By the end, however, the 41-year-old had allowed six runs on seven hits through just three innings of a 14-5 loss to the Seattle Mariners.

Nelson Cruz did most of the damage, following an infield single and two hit batters with a towering grand slam to centre field to put the Mariners up 4-1 in the second inning. Before the game was over Cruz would go deep once more with a three-run shot off reliever Drew Storen in the eighth to punctuate the win.

"It just happened pretty quickly," Dickey said. "I never felt like I was out of control of the game.

"(The knuckleball) was coming out of my hand with good velocity and fairly good movement, I was getting a good amount of swings and misses with it, it was just a really bizarre outing."

Dickey (7-11) scuffled all through his brief start — his shortest since going 2 2/3 innings on May 26, 2011. He loaded the bases on two separate occasions, hit two batters, issued two walks and struck out three while throwing just 72 pitches.

He faced four batters in the fourth inning but failed to get an out.

"I thought he had a pretty good knuckleball early on," manager John Gibbons said. "What killed him was he hit those two guys and Cruz came up and hit the grand slam. ... It was just one of those days, you know? They have a pretty good hitting team over there."

Norichika Aoki had two RBIs for the Mariners (50-47), Seth Smith plated another run and Corey Seager tagged Jesse Chavez with a two-run shot on a day that Toronto's pitching floundered in 33 C heat at Rogers Centre.

The only Blue Jays pitchers not charged with a run were Pedro Morales, who came in to replace Dickey in the fourth, Bo Schultz, who relieved Chavez in the sixth, and Joe Biagini, who pitched a clean ninth.

Chavez allowed five runs on six hits over 2/3 of an inning while Storen walked one and gave up two hits, including Cruz's three-run shot, in one inning of work.

"Neither one of them had pitched in a while," Gibbons said. "Hey, (it's) one of those days where everybody gets caught. Things start going south like that usually everybody gets victimized."

Hisashi Iwakuma (11-6) got the win, striking out three and allowing two runs on four hits and three walks over six innings.

Michael Saunders hit two homers for the Blue Jays (54-44), Justin Smoak hit a two-run blast and Josh Thole had a sacrifice fly.

The Mariners outhit Toronto 19-8.

Thole gave Toronto a 1-0 lead in the second inning, hitting a sac fly to shallow left field to score Kevin Pillar from third base. The throw from Aoki was just wide of the plate, allowing Pillar to slide in safely.

The Mariners tacked on five runs in the sixth off Chavez. Aoki earned his second RBI with a base hit and Smith followed with an RBI single to put the Mariners up 8-1.

A double play off Cruz's bat scored Seattle's ninth run before Seager hit his two-run shot to centre. Schultz ended the inning on a ground-ball out from former Blue Jay Adam Lind.

Storen started the eighth inning with a walk and ground-rule double before Cruz's second homer sent most of the 47,517 fans to the exits. Storen struck out Seager, gave up a single to Lind and got a double play to end the inning.

"I think it's a great ballpark, great hitter's ballpark," Cruz said. "So I guess you feel more comfortable."

Toronto responded in the bottom half of the eighth with two homers, a solo shot from Saunders and a two-run blast from Smoak.

It was the eighth career multi-homer game for Saunders, who also went deep on Friday night.

NOTES: The Blue Jays reinstated Chris Colabello off the restricted list before the game and designated him off their 25-man roster. Colabello, who was suspended 80 games in April after testing positive for a banned substance, remains on Toronto's 40-man roster. His suspension ended on Saturday.