MANSFIELD – On the eve of a widely anticipated U.S. tour, The Who were rocked when founding bassist John Entwistle died suddenly in a Las Vegas hotel on June 27.

His surviving bandmates were immediately thrust into a “damned if you, damned if you don’t” scenario: Either cancel the tour and leave hundreds of thousands of ticket holders disappointed, or carry on and risk accusations of being motivated by greed.

Guitarist Pete Townshend and singer Roger Daltrey decided to carry on. For better or worse, one thing is certain – they are playing their hearts out on this tour.

The Who stormed into the Tweeter Center Friday, and for a full house of more than 19,000 fans they proved once again why they have been one of the most enduring acts in the history of rock ’n’ roll.

Entwistle’s spot on stage was filled quietly but competently by British session man Pino Palladino. Yet it was drummer Zak Starkey, the son of Ringo Starr, who gave the show plenty of its firepower. Like the band’s long-deceased original drummer Keith Moon, Starkey bashes away with authority. But he also showed an innate ability to maintain a rock solid backbeat, so essential to holding The Who’s brand of sonic madness together.

Augmented as well by keyboardist John “Rabbit” Bundrick, Daltrey and Townshend were in exceptional form throughout more than two hours on stage. They spun back to 1964 by opening with “I Can’t Explain,” and they proceeded to tear through fellow early classics “Substitute,” and “Anyway, Anyhow, Anywhere.” Townshend’s trademark windmill guitar blasts were on full display during the latter, which was followed by an even stronger version of their late 1970s slap back at punk rock, “Who Are You.”

The set was peppered with such obscurities as “Relay” and “Another Tricky Day,” and the band even turned in a slightly ragged but intriguing version of its rarely performed 1967 hit “I Can See For Miles.”

All that seemed like a warm-up though, compared to the completely over-the-top version of “Baba O’Riley,” complete with cool keyboard runs, its timeless references to teen-age wasteland and a raging Daltrey harmonica solo.

At 58, Daltrey still possesses one of rock’s most amazing voices, and he sounded stronger Friday than he has during some appearances in recent years. Swinging his microphone by its cord, he shined on “Love Reign O’er Me,” hitting the high notes with raucous power, and delivered equally convincing versions of songs such as “Behind Blues Eyes,” and the pulverizing “My Generation.” Visually noting the latter song’s irony, he rolled his eyes skyward on the key line “Hope I die before I get old.”

A day prior to the concert, a Las Vegas coroner attributed Entwistle’s death to a heart attack caused by cocaine use, a fact which did not go unnoticed by Townshend.

“Some of us are still here,” the guitarist said with a sly grin. “Some of us are still careful about what we eat and drink . . . I saw the report on the news. We might not be having as good a time as John was having in Las Vegas. But we’re pretty sure he was enjoying himself – it’s not to be recommended.”

With that the band proceeded into a lovely acoustic-flavored version of “The Kids Are Alright.” Other latter set standouts included a full-throttle “Won’t Get Fooled Again,” and encores highlighted by “Pinball Wizard,” and “See Me, Feel Me,” both from the groundbreaking epic “Tommy.”

Fellow 1960s rocker and Led Zeppelin lead singer Robert Plant opened the night with an uneven set, much of it culled from his new solo disc “Dreamland.” His performance included a song best known via Jimi Hendrix, “Hey Joe,” as well as the Youngblood’s “Darkness, Darkness,” and tasty takes of vintage Zeppelin material including “Going to California,” “Four Sticks,” and “Babe I’m Gonna Leave You.”

Kevin O’Hare can be reached at kohare@union-news.com