A British triathlete who secured a podium finish after a rival runner allowed him to pass after he took a wrong turn has promised he would do the same.
However, as the 24-year-old Briton looked on in despair, he saw Mentrida slow down and let him cross the finishing line ahead of the Spaniard to claim third place.
Loughborough-based Teagle, who competes for the Spanish Alusigma Penota Triatlon team, told the PA news agency: "I owe him a beer, for sure."
He added: "I'm actually racing him this weekend, so I owe him, if he does the same thing, to let him go past. I'd look a right villain if not."
The event took place last weekend, but video footage of the dramatic conclusion has since been shared widely on social media and Mentrida showered with praise.
Teagle said: "Essentially I get to the finishing chute and there are two ways to go and I choose the way with the big red arch in front of me and keep running that way until the crowd shout, 'You're going the wrong way!' in Spanish.
"I turned around and there's Diego 50m the other way from the actual finish chute and we both start sprinting.
"In the video, you can see me run through and crash into the barrier and I put my arm up – I was frustrated because I'd made a stupid mistake – and that's when Diego stops, to my surprise.
"I wouldn't have held it against him if he didn't. He shows great integrity and sportsmanship and let's me pass.
"You can see in the video, I'm a bit confused still as to where the finish line is, but it was great sportsmanship. I'm glad it's gone viral, I'm glad it's putting a smile on people's faces."
Mentrida's incredible display of sportsmanship, which came after competitors had battled it out over a 1.5km swim and 40km on the bikes before taking to the roads, left Teagle almost speechless.
He said: "There was a full range of emotions, and obviously you're really tired a the end of a race as well. It was incredible, but that's kind of what you get in sport sometimes.
"It never usually goes your way, it's very rare that it goes exactly how you want it to, but to see that integrity, that's incredible. It took me by surprise, I'll be honest.
"I shook his hand really quickly initially because I didn't know where the finish line was still and then shook his hand again afterwards and said, 'Thank you very much, that was incredible'."
Mentrida told Eurosport after the race: "When I saw that he had missed the route, I just stopped. James deserved this medal."
The incident rekindled memories of the day Britain's Alistair Brownlee helped his exhausted brother Jonny over the finishing line in Mexico in an ultimately vain attempt to preserve his hopes of lifting the 2016 World Triathlon crown.
Teagle has vowed to brush up on his Spanish – he admits to making "slow progress" in his efforts to learn the language – but concedes there will be implications too for his domestic life.
He said: "I can't get into an argument with my girlfriend about which way Google Maps is sending us, can I? I've got not a leg to stand on."