US Open champion Daniil Medvedev made a smooth return to ATP action Saturday, downing American Mackenzie McDonald 6-4, 6-2 to reach the third round at Indian Wells.

The second-ranked Russian -- the top men's seed in the combined WTA and ATP Masters hard court tournament -- played his first ATP match since capturing his maiden Grand Slam title at Flushing Meadows -- where he denied Novak Djokovic a rare calendar Grand Slam sweep.

Since then, Medvedev helped Team Europe beat Team World at the Laver Cup, and kept things rolling with a convincing win over 57th-ranked McDonald.

Medvedev didn't face a break point, and converted three of his seven break chances against the American to wrap things up in 72 minutes.

"I'm actually really pleased, because usually I haven't played well in Indian Wells and I haven't been playing that well in practices before (the tournament)," said Medvedev, who was 3-3 in prior appearances in the California desert.

"Mackenzie is a really strong opponent, he can put pressure on everybody," he added. "I'm happy to be through quite fast."

Medvedev booked a third-round meeting with Serbian Filip Krajinovic, who pulled off a 7-6 (7/2), 7-5 winner over American Marcos Giron.

Russian fourth seed Andrey Rublev also advanced, beating Spain's Carlos Taberner 6-3, 6-4.

Women's top seed Karolina Pliskova eased into the third round as fifth-seeded Garbine Muguruza was toppled by Ajla Tomljanovic.

Pliskova, ranked third in the world, needed 80 minutes to get past 23-year-old Polish qualifier Magdalena Frech 7-5, 6-2.

Lean in: Australian Ajla Tomljanovic on the way to a second-round victory over fifth-seeded Garbine Muguruza of Spain at the WTA and ATP Masters Indian Wells hard court tournament
Lean in: Australian Ajla Tomljanovic on the way to a second-round victory over fifth-seeded Garbine Muguruza of Spain at the WTA and ATP Masters Indian Wells hard court tournament GETTY IMAGES NORTH AMERICA / CLIVE BRUNSKILL

Pliskova fired six aces to take her WTA-leading tally to 387 for the season, converting five of six break chances against Frech.

It was the 106th-ranked Frech who grabbed the first break of the match, taking a 4-3 lead in the opening set.

But Pliskova promptly broke back, and leading 6-5, the Czech gave herself a set point with a backhand winner before Frech fired into the net.

Pliskova powered to a 5-1 lead in the second set and, after dropping her serve while serving for the match, broke Frech for the fifth time to claim the win.

Spain's Muguruza, meanwhile, was bundled out 6-3, 1-6, 6-3 by Australia's Tomljanovic, who reached her first Grand Slam quarter-final at Wimbledon earlier this year.

Muguruza appeared to have turned things around when she pocketed the second set to level the match -- aided by a rise in errors from the Aussie.

But Tomljanovic regrouped, breaking Muguruza in the opening game of the third.

Muguruza pulled the break back to knot the set at 3-3, only to drop her serve again, and Tomljanovic finished it off with a final service break.

Bianca Andreescu launched her defense of the title she won in 2019 -- the most recent edition of the tournament -- with a hard-fought 7-6 (7/2), 5-7, 6-2 victory over American Alison Riske.

"It felt great being back here," Andreescu told the crowd of returning to the site of her breakthrough WTA win, which launched her on a stellar 2019 season that included a US Open victory.

"I felt all the emotions of being on this court again," added the Canadian, who has battled injuries since her breakout campaign.

In other women's matches, French Open champion Barbora Krejcikova, the third seed, beat Kazakh qualifier Zarina Diyas 6-4, 3-6, 6-1.