Chris Evert and Tracy Austin won fourth-round matches in the U.S. Open tennis championships yesterday and will meet each other in a quarterfinal this week.

Evert, the second seed behind Wimbledon champion Martina Navratilova, defeated Regina Marsikova, 6-4, 6-1. Austin, 15, the fifth seed, downed junior rival Anne Smith, 6-4, 6-3.

In another match, Kathy May toppled No. 7 seed Betty Stove, 6-4, 7-6.

Pam Shriver of Lutherville, Md., also advanced to the quarters with a 6-2, 6-3 triumph over eighth-seeded Kerry Reid. Shriver next takes on Lesley Hunt, who beat 17-year-old Lele Ferood, 6-3, 3-6, 6-3.

Evert, who has won the U.S. title the last three years, had a difficult time with the 19-year-old Czech in the first set before breaking for 3-5. In the next game, Marsikova ran off three points in a row. Evert saved one break point but lost the game on the next when her forehand shot, hit on the run, went wide.

Evert broke back easily in the next game, and Marsikova's energy seemed to evaporate in the next set.

Austin had a tough match in spots from Smith, 19, who got the first break for 0-2. Austin responded immediately with a break of her own but Smith broke again for 1-3. Austin, however, began playing more cleverly and, from 4-1 down, she won five games in a row for the set.

Austin ran up a 5-2 lead in the second set. Smith broke for 3-5, but Austin had little difficulty breaking service in the final game for the match.

Although Evert has beaten her in their only two meetings, including a center-court match at Wimbledon last year, the 5-foot-3 Austin feels she can provide better competition this time.

"I don't feel the pressure playing Chris; I don't know why," Austin said. "I'll have to play really well but I can't say what I'll do. She'd read it in the morning.

Austin said she has improved a good deal since her last match against Evert.

"Last year, I felt I was super weak. I'm not saying I'll do any better, but now I'm stronger. My serves have improved definitely. I think I've improved it just over the summer, even in the last three weeks. My ground-strokes are stronger and I've worked on my volleys."

Evert, following her victory over Marsikova, went directly to the dressing room to pack her right knee in ice. She had banged the knee earlier against a chair.

"There's nothing wrong," Evert said. "It's just that when I play on cement, if I don't take care of my legs, I could have an injury. I'll really feel it the first tough match.

Evert said she expected Austin to provide tougher competition this year, saying, "I'm sure since she's grown a couple of inches and gotten a little heavier, she's a lot stronger."