The Maryland General Assembly's battle against drunk driving won its first floor victory tonight as the Senate voted overwhelmingly to raise the legal drinking age for beer and wine from 18 to 19.

"It's quite obvious to everyone that we made a mistake in 1974 when we lowered the drinking age [from 21 to 18]," said Sen. H. Erle Schafer (D-Anne Arundel County), the prime sponsor of the bill, which was cosponsored by more than half the Senate. "Let's send a message to the body across the hall that we want to correct that mistake."

The "message" was intended for Del. Joseph E. Owens (D-Montgomery), chairman of the House of Delegates Judiciary Committee, who has killed the drinking age measure for the last two years after it sailed through the Senate much as it did tonight.

Owens has shown no sign of warming to the measure this year, even though drunk driving has become the bandwagon issue of 1981, prompting the introduction of more than 80 bills, including a package sponsored by Gov. Harry Hughes.

Owens, who favors alternate legislation that would penalize underage drinkers by taking away their driving privileges, was standing just outside the Senate chamber as that body voted 33 to 5 in support of the drinking age bill. Told of the vote, he muttered: "What a bunch of frauds."

The bill would outlaw the purchase or consumption of beer and wine in Maryland by person younger than 19, while still allowing 18-year-olds to serve liquor in restaurants. The legal drinking age for hard liquor would remain 21. A similar bill passed the Virginia legislature last month, but it raised the legal age to 19 only for carryout purcahses of beer and wine, not for drinking in bars.

A few senators spoke out sternly against the measure, saying that it punished 18-year-olds rather than attacking the full-scale drunk driving problem, which police officers say has caused an epidemic of tragic deaths in recent years. But the sponsors took the floor to say that the bill offers a way to keep alcoholic beverages out of the schools by making them off limits to high school seniors, and by extension, to their younger classmates.

Sen. Authur Dorman (D-Prince George's), an opponent of the bill but a strong supporter of other anti-drunk driving legislation, urged his colleagues to rally "as strong a vote for [Hughes'] bills as we have for this one."

The administration's package of legislation, which passed Senate committees last week, would toughen enforcement of current drunk driving laws at the arrest, trial and sentencing stages. The bills would lower the percentage of alcohol in the blood required to constitute drunkenness, increase the penalty for refusal to take a drunk driving test and wipe out the exemption that now allows professional drivers to keep their licenses after committing drunk driving violations.

The Hughes bills would also increase the sentence for homicide caused by drunk drivers.

"This puts us in the forefront of the nation in attacking the causes of drunk driving ," Sen. Francis X. Kelly (D-Baltimore County) said of the administration package, which he helped draft as a member of a special task force that studied alcohol abuse by motorists.