It's very common for wrestlers to refer to each other by last name, and for commentators to use surnames 90% of the time.
A lot of examples involve a two-part ring name (may or may not be their real name) which had the first name taken out of official billing but was still referenced on-screen by other performers at times:
Dave Batista and Dave "Fit" Finlay, whose respective ring names are their actual last names (Batista's with a minor spelling change from "Bautista"). Batista gets a "Dave" every now and then, however, a bit more frequently than Finlay would even get a "Fit" in WWE in fact.
Then there's Ken Anderson/Kennedy, who insisted on being referred to as "Mr. Kennedy" - and insisted on referring to himself as "Mister Kennedy....Kennedy!" Since his jump to TNA, he's gone by 'Mr. Anderson'.
Vince McMahon's name on the official WWE website and on most official WWE products such as WWE magazine is listed as simply "Mr. McMahon."
Bill Goldberg dropped his first name during his monster push in WCW.
TNA's Kazarian used to be called Frankie Kazarian, but dropped the first name.
Bobby Lashley was often referred to as "Mr. Lashley" or simply "Lashley". Teddy Long always called him "Bobby," though.
Before he was JBL, John Bradshaw Layfield was known as Justin 'Hawk' Bradshaw. He dropped his first name and his nickname when he was paired up with Faarooq to form 'The Acolytes'.
This is almost completely subverted with the WWE Divas. So infrequently does Last Name Basis occur, that many Divas don't even have last names. Sometimes it's a first and last that are rarely separated (Gail Kim, Rosa Mendes) or a last name that is only used extremely rarely (Jillian Hall, Eve Torres) or simply only being known by their first name (Melina, Layla, Maryse). Michelle McCool seems to be the one exception to this, but in her case, it is a 50-50 basis.
When a wrestler's last name is that of a major wrestling legacy, such as McMahon, Hardy, Hart, Guerrero, DiBiase, or Rhodes, they are often referred to by their first name, especially when two people are involved at once.
This is especially used in the case of Vickie Guerrero, probably because she is a woman.
Nowadays, the only male wrestler (who doesn't fit the "family" example above) better known by his first name than by his last name is Santino Marella.
He did have last name basis in the earlier parts of his career, but when his gimmick became a comedy gimmick, this was swapped.
Kofi Kingston may also be an example, but that is nowhere near the extreme of Santino's case.
Raven's Flock in WCW were all over the map with this one. Billy Kidman and Scotty Riggs were increasingly referred to by their Kayfabe last names after joining the group. Reese (Ron Reis, aka the Yeti of the Dungeon of Doom) used an altered version of his real last name. Horace Boulder, however, was referred to generally as "Horace" until he joined the NWO and started using the name Horace Hogan.note Horace, real name Mike Bollea, is Hulk Hogan's nephew.