OPINION
FIDEL, Chief Judge.A construction worker, injured on the job, attributes partial responsibility to the general contractor, claiming that the general contractor neglected safety responsibilities that it had contractually assumed. We consider in this appeal whether the trial court properly granted summary judgment to the general contractor on the theory that it owed no duty to its subcontractor’s employee.
FACTS
On appeal from summary judgment, we review facts and inferences in the light most favorable to the party opposing the motion. Hill-Shafer Partnership v. Chilson Family Trust, 165 Ariz. 469, 472, 799 P.2d 810, 813 (1990).
Plaintiff Anthony Richard Vega, Jr., worked on the Yuma Detention Center project as an employee of Liberty Steel & Maintenance Company. Liberty Steel was a subcontractor to Engineered Specialty Products, Inc. (“ESP”), which in turn was a subcontractor to the general contractor, defendant Griffiths Construction, Inc. (“Griffiths”).
Plaintiff was injured while installing chain link security fencing on top of a wall that surrounded the prison recreation yard. While working at least twenty feet above ground on a scaffolding plank attached to a forklift’s prongs, plaintiff braced one of his feet against the horizontal bar of a previously-installed section of the fence. The horizontal bar was attached to a vertical bar by means of a T-clamp designed and manufactured by ESP. The T-clamp, unable to bear plaintiff’s weight, gave way, and plaintiff took a long fall to the ground.
Plaintiff received worker’s compensation benefits through ESP, and he filed suit against Griffiths and others not party to this appeal. The trial court granted Griffiths’ motion for summary judgment, finding that Griffiths owed plaintiff no duty of care. Plaintiff timely appealed.
DISCUSSION
Disposition of the duty issue is controlled by our supreme court’s recent decision in Lewis v. N.J. Riebe Enter., 170 Ariz. 384, 825 P.2d 5 (1992). The supreme court there made clear that liability may flow from a general contractor’s neglect of its duty to provide a reasonably safe workplace to subcontractors’ employees. Id. at 392, 825 P.2d at 13. The evidence in this case permits the conclusion that Griffiths both contractually assumed and affirmatively exercised that duty. As the trial court based its judgment on a finding of no duty, this evidence requires us to reverse.1
A. Contractually-Retained Safety Control
The contract between Griffiths and Yuma County made Griffiths solely “responsible for initiating, maintaining and supervising all safety precautions and programs in connection with the Work.” The contract also obliged Griffiths to “take all reasonable precautions for the safety of ... all employees” and “designate a responsible member of his organization at the site whose duty shall be the prevention of accidents.”
*48These identical provisions were found in Lewis to subject the general contractor to an “affirmative duty to control [the subcontractor’s] work methods in order to insure the safety of everyone at the work site.” Id. The court paraphrased the Restatement to define the liability that flows from negligent exercise of a contractual undertaking of this kind:
[W]e hold that if a general contractor contractually assumes the responsibility for safety at a work site, it is liable for any injury resulting from its negligent exercise of that responsibility as long as the general contractor “[knew] or by the exercise of reasonable care should [have known] that the subcontractors’ work [was being done in a dangerous manner], and ha[d] the opportunity to prevent it by exercising the power of control which he ... retained in himself.” Restatement (Second) of Torts § 414 comment (b) (1965).
Id.
We conclude that Griffiths’s contractual undertaking alone suffices to negate the trial court’s finding of no duty.
B. Affirmative Exercise of Safety Control
A factfinder in this case could additionally conclude that Griffiths affirmatively exercised its contractual safety control. Project Manager Harlyn Griffiths, Jr., testified at deposition that he and another Griffiths representative were designated to oversee safety at the job site, that he walked the job daily, and that he would instruct subcontractors to take safety precautions if he found that they had neglected to do so.2 Liberty Steel owner Charlie Walker likewise testified that Harlyn Griffiths, Jr., supervised safety at the site. A general contractor is liable, according to Lewis, if its safety manager exercises such authority negligently. Id. at 393, 825 P.2d at 14.
C. Other Theories
The trial court did not reach questions of negligence or causation; nor do we. We hold only that the trial court erred in finding that Griffiths owed the plaintiff no duty. In reversing the summary judgment on this ground, we do not disturb the trial court’s rejection of plaintiffs’ theories of product liability and implied warranty against Griffiths. Even if we ignore plaintiff’s utter inability to show that the T-clamp was unsuitable for a reasonably foreseeable use, there is no evidence that Griffiths designed, sold, or warranted the T-clamp or placed it in the stream of commerce. Indeed, the T-clamp was not placed in the stream of commerce at all.3 The record indicates, rather, that the T-clamp was a creature wholly of ESP’s production, produced for this job alone. The trial court correctly rejected plaintiffs’ theories of recovery on product liability and warranty grounds.
CONCLUSION
Because the evidence establishes that Griffiths owed a duty to the plaintiff, we reverse the trial court’s order granting summary judgment in favor of Griffiths and remand for further proceedings.
GERBER, J., concurs.. In a special concurring opinion, our colleague criticizes Lewis as wrongly decided. Without belaboring points that the supreme court has dispositively made, we simply note—lest silence be taken as joinder—that we do not share our colleague’s view.
. This portion of Harlyn Griffiths's deposition was quoted by plaintiffs in their opening brief with a citation indicating that it was part of the record in the trial court. Although it was not transmitted to this Court in the record on appeal, Griffiths has not challenged its use or accuracy.
. As we concluded in our memorandum decision in a related appezd, Vega v. Engineered Specialty Products, Inc., 1 CA-CV 89-198, slip op. at 8 (App. Oct. 1, 1991), “ESP ... manufactured the T-clzunp in this isolated instzmce, and was not in the business of manufacturing and selling T-clzunps for general consumption. ESP designed the T-clzunp solely for this particular project. We cztnnot say that ESP’s actions placed the T-clamp in the general stream of commerce____"